[ { "key": "2WL43VNZ", "version": 918, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/2WL43VNZ", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/2WL43VNZ", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Choi et al.", "parsedDate": "2026-01-05", "numChildren": 0 }, "data": { "key": "2WL43VNZ", "version": 918, "itemType": "journalArticle", "title": "Absolute Radiometric Calibration of CAS500-1/AEISS-C: Reflectance-Based Vicarious Calibration and Cross-Calibration with Sentinel-2/MSI", "creators": [ { "creatorType": "author", "firstName": "KB", "lastName": "Choi" }, { "creatorType": "author", "firstName": "KW", "lastName": "Jin" }, { "creatorType": "author", "firstName": "DH", "lastName": "Cha" }, { "creatorType": "author", "firstName": "JH", "lastName": "Choi" }, { "creatorType": "author", "firstName": "YH", "lastName": "Jo" }, { "creatorType": "author", "firstName": "KN", "lastName": "Kim" }, { "creatorType": "author", "firstName": "GB", "lastName": "Kang" }, { "creatorType": "author", "firstName": "HY", "lastName": "Shin" }, { "creatorType": "author", "firstName": "JY", "lastName": "Lee" }, { "creatorType": "author", "firstName": "EY", "lastName": "Kim" }, { "creatorType": "author", "firstName": "YG", "lastName": "Lee" } ], "abstractNote": "Highlights What are the main findings? This study presents, to the best of our knowledge, the first absolute radiometric calibration of CAS500-1/AEISS-C via two methods: (1) reflectance-based vicarious calibration and (2) cross-calibration with Sentinel-2/MSI (applying SBAF and MODIS MCD43A1-based BCF). Both methods yielded strong linear fits (R2 = 0.70-0.97 for vicarious calibration; R2 = 0.90-0.98 for cross-calibration). Since CAS500-1/AEISS-C employs a TDI CCD sensor, gain values were resolved for each seasonally varying TDI mode as follows: vicarious calibration (Blue, Green, Red, NIR, PAN)-0.08, 0.07, 0.10, 0.10, 0.08 (TDI mode 1)/0.21, 0.15, 0.19, 0.12, 0.16 (TDI mode 2); cross-calibration (Blue, Green, Red, NIR)-0.08, 0.06, 0.10, 0.07 (TDI mode 1)/0.21, 0.10, 0.18, 0.08 (TDI mode 2). What are the implications of the main findings? This on-orbit absolute radiometric calibration of CAS500-1/AEISS-C highlights the need for continued coefficient updates and performance monitoring throughout the satellite's operational period to ensure consistent image accuracy and reliability. For TDI CCD-based satellite sensors, absolute radiometric calibration should incorporate TDI in the derivation of coefficients.Highlights What are the main findings? This study presents, to the best of our knowledge, the first absolute radiometric calibration of CAS500-1/AEISS-C via two methods: (1) reflectance-based vicarious calibration and (2) cross-calibration with Sentinel-2/MSI (applying SBAF and MODIS MCD43A1-based BCF). Both methods yielded strong linear fits (R2 = 0.70-0.97 for vicarious calibration; R2 = 0.90-0.98 for cross-calibration). Since CAS500-1/AEISS-C employs a TDI CCD sensor, gain values were resolved for each seasonally varying TDI mode as follows: vicarious calibration (Blue, Green, Red, NIR, PAN)-0.08, 0.07, 0.10, 0.10, 0.08 (TDI mode 1)/0.21, 0.15, 0.19, 0.12, 0.16 (TDI mode 2); cross-calibration (Blue, Green, Red, NIR)-0.08, 0.06, 0.10, 0.07 (TDI mode 1)/0.21, 0.10, 0.18, 0.08 (TDI mode 2). What are the implications of the main findings? This on-orbit absolute radiometric calibration of CAS500-1/AEISS-C highlights the need for continued coefficient updates and performance monitoring throughout the satellite's operational period to ensure consistent image accuracy and reliability. For TDI CCD-based satellite sensors, absolute radiometric calibration should incorporate TDI in the derivation of coefficients.Abstract The absolute radiometric calibration of a satellite sensor is an essential process that determines the coefficients required to convert the radiometric quantities of satellite images. This procedure is crucial for ensuring the applicability and enhancing the reliability of optical sensors onboard satellites. This study performs the absolute radiometric calibration of the Compact Advanced Satellite 500-1 (CAS500-1) Advanced Earth Imaging Sensor System-C (AEISS-C), a low Earth orbit satellite developed independently by Republic of Korea for precise ground observation. Field campaign using a tarp, an Analytical Spectral Devices FieldSpecIII spectroradiometer, and a MicrotopsII sunphotometer was conducted. Additionally, reflectance-based vicarious calibration was performed using observational data and the MODerate resolution atmospheric TRANsmission model (version 6) radiative transfer model (RTM).\nCross-calibration was also performed using data from the Sentinel-2 MultiSpectral Instrument, RadCalNet observations, and MODIS Bidirectional nReflectance Distribution Function (BRDF) products (MCD43A1) to account for differences in spectral response functions, viewing/solar geometry, and atmospheric conditions between the two satellites. From these datasets, two correction factors were derived: the Spectral Band Adjustment Factor and the BRDF Correction Factor. CAS500-1/AEISS-C acquires satellite imagery using two Time Delay Integration (TDI) modes, and the absolute radiometric calibration coefficients were derived considering these TDI modes. The coefficient of determination (R2) ranged from 0.70 to 0.97 for the reflectance-based vicarious calibration and from 0.90 to 0.99 for the cross-calibration. For reflectance-based vicarious calibration, aerosol optical depth was identified as the primary source of uncertainty among atmospheric factors. For cross-calibration, the reference satellite and RTMs were the primary sources of uncertainty. The results of this study will support the monitoring of CAS500-1/AEISS-C, which produces high-resolution imagery with a spatial resolution of 2 m, and can serve as foundational material for absolute radiometric calibration procedures for other CAS500 satellites.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2026 JAN 5", "volume": "18", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs18010177", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001657678600001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "KPGCHHDD", "version": 918, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/KPGCHHDD", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/KPGCHHDD", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Hu et al.", "parsedDate": "2026-03-01", "numChildren": 0 }, "data": { "key": "KPGCHHDD", "version": 918, "itemType": "journalArticle", "title": "Global retrieval of harmonized microwave land surface emissivity leveraging multi-sensor measurements from GMI, AMSR2 and MWRIs", "creators": [ { "creatorType": "author", "firstName": "Jiheng", "lastName": "Hu" }, { "creatorType": "author", "firstName": "Rui", "lastName": "Li" }, { "creatorType": "author", "firstName": "Peng", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Yu", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Shengli", "lastName": "Wu" }, { "creatorType": "author", "firstName": "Husi", "lastName": "Letu" }, { "creatorType": "author", "firstName": "Fuzhong", "lastName": "Weng" } ], "abstractNote": "Accurate accounting of microwave land surface emissivity (MLSE) facilitates applications associated with monitoring the ecohydrological dynamics in global terrestrial ecosystems, quantifying cross-sphere carbon and water exchanges, and meeting the critical accuracy required for assimilation in the global precipitation retrieval algorithm. However, collaborative applications of emissivity retrieved from individual sensors are severely hampered by discrepancies in retrieval techniques, instrumental configurations, calibration errors, and broken temporal periods. To mitigate this gap, we present an innovative framework to retrieve harmonized emissivity from observations of five passive microwave sensors, namely, GPM-CO/GMI, Fengyun-3B, −3C and −3D/MWRI, and GCOM-W1/AMSR2. Six geostationary visible and infrared imagers onboard three geostationary platforms, i.e. GOES-16/ABI, Himawari-8, −9/AHI, and MSG-1, −2, −3/SEVIRI, were collocated to jointly provide clear-sky masks covering the globe. The simultaneous conical overpass (SCO) recalibration technique was applied to scale all emissivity subsets retrieved from different sensors to be aligned with the GMI retrievals across various land types. Quantitative analyses reveal exceptionally strong consistency among emissivities across different subsets (Pearson R ≈ 0.95, RMSD <0.011, and mean bias within ±0.005). Our estimates at 10.65 GHz show strong agreement with in-situ radiometer measurements over two grass and crop fields, with errors generally within ±0.01 at vertical polarization and a systematic underestimation of approximately −0.02 at horizontal polarization. Globally, we evaluate the recalibrated emissivities against four reference datasets derived using various techniques, which includes three single-sensor retrievals from GMI and AMSR-E, as well as a climatology emissivity atlas generated using the Tool to Estimate Land Surface Emissivity at Microwaves and Millimeter waves (TELSEM). The results demonstrate strong consistencies at both vertical (R = 0.8–0.9, RMSD <0.015 or ∼ 1.5 %) and horizontal (R = 0.9–0.95, RMSD <0.02 or ∼ 2 %) polarizations on a monthly scale. The observed discrepancies are primarily attributed to differences in instrumental configurations, calibration accuracy, and retrieval methodologies. The harmonized retrieval algorithm and the sophisticated cross sensor calibrations facilitate its implementation as a self-consistent emissivity data for various applications associated with terrestrial ecohydrological dynamics, surface hydrological properties estimation, as well as the physical-based precipitation retrieval algorithms over land.", "publicationTitle": "Remote Sensing of Environment", "publisher": "", "place": "", "date": "2026-03-01", "volume": "334", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "115169", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Remote Sensing of Environment", "DOI": "10.1016/j.rse.2025.115169", "citationKey": "", "url": "https://www.sciencedirect.com/science/article/pii/S0034425725005735", "accessDate": "2026-02-09T12:36:51Z", "PMID": "", "PMCID": "", "ISSN": "0034-4257", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "NI3XJ5KM", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/NI3XJ5KM", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/NI3XJ5KM", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Stedman et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "NI3XJ5KM", "version": 917, "itemType": "journalArticle", "title": "Impact of Characterization on Cross-Calibration Performance for Multispectral Sensors With SI-Traceable Satellite Mission TRUTHS", "creators": [ { "creatorType": "author", "firstName": "M", "lastName": "Stedman" }, { "creatorType": "author", "firstName": "SE", "lastName": "Hunt" }, { "creatorType": "author", "firstName": "P", "lastName": "De Vis" }, { "creatorType": "author", "firstName": "R", "lastName": "Bantges" }, { "creatorType": "author", "firstName": "H", "lastName": "Brindley" }, { "creatorType": "author", "firstName": "N", "lastName": "Fox" } ], "abstractNote": "A new generation of satellites designed for low-uncertainty, SI-traceable measurements-termed \"SITSats\"-marks a major advancement in Earth observation (EO) capability. These missions aim to enhance the performance and interoperability of the EO \"system of systems.\" Among them, the ESA Earth Watch Traceable Radiometry Underpinning Terrestrial- and Helio-Studies (TRUTHS) mission is designed to serve as a \"gold-standard\" radiometric reference for cross-calibrating EO sensors in the solar reflective domain. In this work, uncertainties in cross-calibration comparisons arising from sensor characterization and design are investigated. A processing chain to prepare collocated data for uncertainty-quantified comparison is presented. This includes steps to perform spectral band adjustment and spatial resampling. Using the TRUTHS hyperspectral imaging spectrometer (HIS) as the reference and Sentinel-2 multispectral imager (MSI) as the target, a simulation study based on high-resolution imagery assesses achievable comparison performance. A subset of uncertainty effects driven by sensor characterization is propagated through the spectral and spatial processing using a Monte Carlo approach. Sentinel-2 data are assumed at 10-m resolution, which is most sensitive to the errors considered. The results highlight the importance of sensor characterization, particularly inherent in-flight wavelength knowledge for target sensors, in such comparisons. Results from the simulation analysis give uncertainty estimates (k =1) of 0.31% (blue), 0.50% (green), and 0.23% (red) for the combined error effects arising from sensor characterization and geolocation uncertainty for comparisons over the Libya-4 desert pseudo-invariant calibration sites (PICS) using an instantaneous 205-m square comparison region. Results for more heterogeneous scenes, such as rainforest, still achieve uncertainties of 0.6%-1.2% for the red-green-blue (RGB) bands over a 20x 200 m area. The uncertainty is driven largely by the spectral component-up to 1% due to the inherent Sentinel-2 wavelength knowledge of 1 nm across various representative scenes outside of the atmospheric absorption bands. While the impact of these uncertainties may decrease when considering a diverse range of scene types, they introduce systematic errors when scenes share similar spectral characteristics. The impact of some uncertainty contributions, for example, geolocation uncertainty, is shown to be substantially reduced by aggregating samples over larger regions or over longer time periods. This analysis supports the development of low-uncertainty, ideally SITSat-enabled intercalibration approaches needed to ensure radiometric consistency across missions for generating long-term climate data records.", "publicationTitle": "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING", "publisher": "", "place": "", "date": "2025", "volume": "63", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1109/TGRS.2025.3633954", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "0196-2892", "archive": "", "archiveLocation": "WOS:001631862000030", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "D8MM9VX6", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/D8MM9VX6", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/D8MM9VX6", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Tu et al.", "parsedDate": "2026-02-10", "numChildren": 0 }, "data": { "key": "D8MM9VX6", "version": 917, "itemType": "journalArticle", "title": "On-orbit relative radiometric calibration of the wide field-of-view GF-5-02/ DPC sensor based on GOES/ABI", "creators": [ { "creatorType": "author", "firstName": "BH", "lastName": "Tu" }, { "creatorType": "author", "firstName": "PP", "lastName": "Yao" }, { "creatorType": "author", "firstName": "RF", "lastName": "Ti" }, { "creatorType": "author", "firstName": "HX", "lastName": "Yu" }, { "creatorType": "author", "firstName": "LL", "lastName": "Fan" }, { "creatorType": "author", "firstName": "DG", "lastName": "Luo" }, { "creatorType": "author", "firstName": "ZW", "lastName": "Qiu" }, { "creatorType": "author", "firstName": "J", "lastName": "Hong" } ], "abstractNote": "The directional polarimetric camera (DPC) aboard the Hyperspectral Observation Satellite (GF-5-02) has been launched successfully in 7 September 2021. The wide-field relative radiometric calibration for DPC is to minimize pixel-to-pixel response variations to ensure spatial radiometric uniformity. It effectively reduces the errors present in the radiometric data collected from multi-angle observations of a target. This process makes it easier to accurately describe the distribution pattern of the target's reflected radiometric information, thereby enhancing the precision of target property retrieval. Therefore, the relative radiometric calibration is of great significance for wide-field-of-view sensors. Due to the absence of onboard calibrator and the constraints imposed by traditional calibration sites, accurately correcting for non-uniformity in irradiance response across a vast number of DPC pixels continues to pose a significant challenge. Therefore, we propose a novel approach for relative radiometric calibration of wide field-of-view array sensors utilizing large-area high-altitude thick ice clouds as reference targets. The new approach comprehensively considers the requirements for cross-calibration across the spectral range, swath width, and observational synchronicity between two sensors. It employs the data from the Advanced Baseline Imager onboard the Geostationary Operational Environmental Satellite (GOES/ABI) to monitor the relative radiometric properties of the DPC at the polarized bands of 490 nm, 670 nm and 865 nm. The measurement results, covering the period from November 2021 and November 2023, indicate that the annual relative radiometric changes are less than 6 % (4.45 % at 490 nm, 5.07 % at 670 nm, 5.23 % at 865 nm). The attenuation in the edge field of view is less than that in the central field of view. This method verifies the feasibility of monitoring the relative radiometric performance of wide field-of-view sensors using stationary meteorological satellites, providing critical support for the quantitative application of multi-angle observation sensors and offering a new reference technology for radiometric calibration of wide field-of-view and large swath-width sensors.", "publicationTitle": "MEASUREMENT", "publisher": "", "place": "", "date": "2026 FEB 10", "volume": "260", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1016/j.measurement.2025.119821", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "0263-2241", "archive": "", "archiveLocation": "WOS:001629690100007", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "3RDVIP87", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/3RDVIP87", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/3RDVIP87", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Yu et al.", "parsedDate": "2025-12-10", "numChildren": 0 }, "data": { "key": "3RDVIP87", "version": 917, "itemType": "journalArticle", "title": "A Dynamic Gaussian Modified Spectral Band Adjustment Factors Method for Radiometric Cross-Calibration of HJ-2A/HSI with ZY1-02D/AHSI", "creators": [ { "creatorType": "author", "firstName": "C", "lastName": "Yu" }, { "creatorType": "author", "firstName": "XY", "lastName": "Gao" }, { "creatorType": "author", "firstName": "H", "lastName": "Zhao" }, { "creatorType": "author", "firstName": "XP", "lastName": "Feng" }, { "creatorType": "author", "firstName": "J", "lastName": "Cheng" }, { "creatorType": "author", "firstName": "BL", "lastName": "Hu" }, { "creatorType": "author", "firstName": "S", "lastName": "Wang" } ], "abstractNote": "Highlights What are the main findings? A DG-SBAF method was developed to model spectral channels with Gaussian response functions, dynamically matching multiple reference-sensor channels and optimizing SBAF weights. Applied to HJ-2A/HSI-ZY-1-02D/AHSI cross-calibration, the method achieved 12.11% and 8.64% relative improvements in VNIR and SWIR, respectively. What are the implications of the main findings? DG-SBAF mitigates spectral mismatches and enhances radiometric stability. Enables more accurate on-orbit calibration and long-term radiometric consistency among sensors.Highlights What are the main findings? A DG-SBAF method was developed to model spectral channels with Gaussian response functions, dynamically matching multiple reference-sensor channels and optimizing SBAF weights. Applied to HJ-2A/HSI-ZY-1-02D/AHSI cross-calibration, the method achieved 12.11% and 8.64% relative improvements in VNIR and SWIR, respectively. What are the implications of the main findings? DG-SBAF mitigates spectral mismatches and enhances radiometric stability. Enables more accurate on-orbit calibration and long-term radiometric consistency among sensors.Abstract The Huanjing Jianzai-2A (HJ-2A), launched in 2020 as China's civilian operational environmental satellite, exhibits intrinsic non-uniformity from spectral channel distribution and inconsistency from the spectral resolution in its hyperspectral imager (HSI). These spectral characteristics compromise the spectral channel matching process, posing challenges to the traditional cross-calibration method. To overcome these spectral matching constraints, this study proposed a Dynamic Gaussian Spectral Band Adjustment Factors (DG-SBAF) method for cross-calibration that constructs a Gaussian distribution model for each spectral channel of the target sensor, dynamically matches the spectral channels of the reference sensor and optimizes SBAF compensation weights through Gaussian function values. The cross-calibration of HJ-2A/HSI was conducted using ZiYuan1-02D Advanced Hyperspectral Imager (ZY1-02D/AHSI) through three distinct test sites: Dunhuang, Baotou, and Taklamakan Desert. The cross-calibration results analysis across three sites revealed mean relative deviations of 6.46% (VNIR) and 8.67% (SWIR), demonstrating superior performance over the traditional SBAF method (7.35% to VNIR, 9.49% to SWIR). Analyses of SBAF fluctuation showed that the DG-SBAF method achieved SBAF distributions approaching 1 with mean RMSE values of 0.0312 (VNIR) and 0.1086 (SWIR). Validation through spectral consistency assessment showed spectral angles less than 5 degrees and 7 degrees in VNIR bands when compared with Gaofen-5B/AHSI and Land-sat-9/OLI-2, respectively, and less than 6 degrees with GF-5B/AHSI in SWIR bands. The pro-posed method effectively corrects spectral channel discrepancies in the matching process, enhances radiometric stability, and provides effective supplementary on-orbit calibration capability.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2025 DEC 10", "volume": "17", "issue": "24", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs17243988", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001647472100001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "ENNHBSVH", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/ENNHBSVH", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/ENNHBSVH", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Zhang et al.", "parsedDate": "2025-12-01", "numChildren": 0 }, "data": { "key": "ENNHBSVH", "version": 917, "itemType": "journalArticle", "title": "On-orbit cross-calibration of the DPC and POSP sensors onboard the GaoFen-5 (02) satellite", "creators": [ { "creatorType": "author", "firstName": "H", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "ZQ", "lastName": "Li" }, { "creatorType": "author", "firstName": "LL", "lastName": "Qie" }, { "creatorType": "author", "firstName": "H", "lastName": "Xu" }, { "creatorType": "author", "firstName": "SF", "lastName": "Zhu" }, { "creatorType": "author", "firstName": "ZH", "lastName": "Liu" }, { "creatorType": "author", "firstName": "XF", "lastName": "Lei" }, { "creatorType": "author", "firstName": "YS", "lastName": "Xie" }, { "creatorType": "author", "firstName": "MY", "lastName": "Zhu" }, { "creatorType": "author", "firstName": "CW", "lastName": "Lan" }, { "creatorType": "author", "firstName": "J", "lastName": "Hong" } ], "abstractNote": "The directional polarimetric camera (DPC) and the Particulate Observing Scanning Polarimeter (POSP) sensors onboard the satellite constitute the polarization crossfire suite (PCF). It is designed for the global monitoring of atmospheric fine particulate matter from space. The DPC is a wide field-of-view (FOV) multi-angular polarization imager. The POSP is a cross-track scanning polarimeter equipped with an onboard radiometric and polarimetric calibration system. A cross-calibration strategy from POSP to DPC has been designed to ensure their in-flight radiometric consistency. In this study, a detailed analysis of the potential error sources in the cross-calibration process was conducted, including the pixel spatial matching method, the spectral response function (SRF), and viewing geometry discrepancies. Results indicate that higher site homogeneity leads to smaller errors caused by pixel-level spatial mismatch. When site inhomogeneity is constrained to 1%, the calibration error can be limited to 0.05% at nadir and 0.32% at the image edge. Errors caused by viewing geometry discrepancies decrease with wavelength over desert scenes but increase with wavelength over ocean scenes. The errors caused by viewing geometry and SRF discrepancies range from 0.25% to 0.29% over the desert and from 2.03% to 2.91% over the ocean. An optimized PCF cross-calibration workflow is then proposed. It includes the improved strategy for pixel spatial matching and viewing geometry matching. A radiative transfer model is also employed to correct the spectral and viewing geometry differences. This method yields radiometric calibration coefficients highly consistent with those from other vicarious calibration methods and exhibits different spectral performances over ocean and desert scenarios. The radiometric performance of DPC onboard GaoFen-5(02) was further evaluated over its first two and a half years in orbit through cross-calibration with POSP. The 670 nm band of DPC shows the smallest relative radiometric response across the FOV and the highest temporal stability. The 865 nm band shows approximately 1.5% relative radiometric variation and 1.0% temporal degradation. In contrast, the 443 nm band exhibits the largest variation in both relative radiometric response and temporal stability. The relative radiometric difference between the center and edge of the FOV was 5.8% in March 2022. It increased to 9.4% by June 2024. Meanwhile, the absolute radiometric response decreased by about 5.5% over the same period. The 490 nm band performs better than 443 nm. Its relative radiometric response remains within 4.5%. The temporal degradation is about 3.5%. DPC/GaoFen-5(02) exhibits significantly improved in-flight radiometric performance compared to the earlier training, and similar technologies, are reserved.", "publicationTitle": "APPLIED OPTICS", "publisher": "", "place": "", "date": "2025 DEC 1", "volume": "64", "issue": "34", "section": "", "partNumber": "", "partTitle": "", "pages": "10351-10364", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1364/AO.576062", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "1559-128X", "archive": "", "archiveLocation": "WOS:001630942300001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "8UJZHI6E", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/8UJZHI6E", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/8UJZHI6E", "type": "text/html" }, "up": { "href": "https://api.zotero.org/groups/538513/items/5YN25TCM", "type": "application/json" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "numChildren": 0 }, "data": { "key": "8UJZHI6E", "version": 917, "parentItem": "5YN25TCM", "itemType": "note", "note": "

Export Date: 09 February 2026; Cited By: 0

", "tags": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "5YN25TCM", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/5YN25TCM", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/5YN25TCM", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Hao et al.", "parsedDate": "2026", "numChildren": 1 }, "data": { "key": "5YN25TCM", "version": 917, "itemType": "journalArticle", "title": "A Refined Radiometric Cross-Calibration of HJ-2B/IRS over Plateau Lakes Using the Double-Difference Method", "creators": [ { "creatorType": "author", "firstName": "A.", "lastName": "Hao" }, { "creatorType": "author", "firstName": "J.", "lastName": "Han" }, { "creatorType": "author", "firstName": "X.", "lastName": "Zhou" }, { "creatorType": "author", "firstName": "W.", "lastName": "Shao" }, { "creatorType": "author", "firstName": "Y.", "lastName": "Xie" } ], "abstractNote": "The Infrared Scanner (IRS) onboard the HJ-2B satellite is a high-resolution, dual-channel thermal infrared sensor suitable for applications such as land-surface temperature retrieval and smoke detection. Radiometric calibration is a fundamental prerequisite for ensuring the quality and reliability of IRS observation data and is typically performed via two-point (high- and low-temperature) calibration using the instrument's onboard blackbody. However, the effectiveness of this procedure can be constrained by performance degradation of the calibration hardware and by its frequency of usage. In response to these limitations, this article proposes a refined radiometric cross-calibration method for the HJ-2B/IRS sensor over plateau lakes, which adopts the double-difference method as the technical basis and uses the high-accuracy Terra/MODIS as the reference sensor. Implemented through rigorous screening of calibration sites and sampling points, the method explicitly accounts for viewing geometry, as well as contemporaneous surface and atmospheric conditions. Firstly, calibration points between IRS and MODIS are screened by setting a CV threshold and using the RANSAC algorithm. Next, given the surface and atmospheric conditions at the satellite overpass time, radiances at calibration points with large viewing zenith angles were corrected to their nadir-equivalent values, and a temperature-dependent simulated brightness temperature difference function is constructed, from which the fitted calibration coefficients (FCCs) are derived using the double-difference method. Finally, validation with Landsat-8/TIRS indicates that IRS brightness temperatures calculated by the FCCs deviate less from the TIRS observations than those computed with the official calibration coefficients (OCCs) issued by the China Centre for Resources Satellite Data and Application. Furthermore, when compared with the top-of-atmosphere brightness temperatures derived from forward modeling of in situ measurement data, the IRS at-aperture brightness temperature computed using the FCCs shows mean deviations of -1.04 K and -0.92 K for Band 8 and Band 9, respectively. These values are superior to the corresponding deviations of -1.32 K and -2.43 K obtained using the OCCs. Following a quantitative analysis of various factors influencing the FCCs, the total uncertainty for IRS Band 8 and Band 9 was determined to be below 0.937% and 1.257%, respectively. © 2025 IEEE.", "publicationTitle": "IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing", "publisher": "", "place": "", "date": "2026", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1109/JSTARS.2026.3652599", "citationKey": "", "url": "https://www.scopus.com/inward/record.uri?eid=2-s2.0-105027590029&doi=10.1109%2FJSTARS.2026.3652599&partnerID=40&md5=272aba6525bb593d43ece27203bb0a8f", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "Scopus", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Atmospheric humidity" }, { "tag": "Atmospheric temperature" }, { "tag": "Brightness temperatures" }, { "tag": "Calibration" }, { "tag": "Calibration coefficients" }, { "tag": "Cross calibration" }, { "tag": "Difference method" }, { "tag": "Double differences" }, { "tag": "Double-difference method" }, { "tag": "HuanJing-2B (HJ-2B)" }, { "tag": "Huanjing-2b" }, { "tag": "Infrared Scanner (IRS)" }, { "tag": "Infrared detectors" }, { "tag": "Infrared radiation" }, { "tag": "Infrared scanner" }, { "tag": "Infrared scanners" }, { "tag": "Lakes" }, { "tag": "Land surface temperature" }, { "tag": "Luminance" }, { "tag": "Plateau lake" }, { "tag": "Radiometers" }, { "tag": "Radiometry" }, { "tag": "Remote sensing" }, { "tag": "Satellites" }, { "tag": "Signal to noise ratio" }, { "tag": "Smoke" }, { "tag": "Surface measurement" }, { "tag": "cross-calibration" }, { "tag": "double-difference method" }, { "tag": "plateau lakes" } ], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "XLN6VTGC", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/XLN6VTGC", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/XLN6VTGC", "type": "text/html" }, "up": { "href": "https://api.zotero.org/groups/538513/items/U46XP5KZ", "type": "application/json" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "numChildren": 0 }, "data": { "key": "XLN6VTGC", "version": 917, "parentItem": "U46XP5KZ", "itemType": "note", "note": "

Export Date: 09 February 2026; Cited By: 0

", "tags": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "KV3VRY6B", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/KV3VRY6B", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/KV3VRY6B", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Zhou et al.", "parsedDate": "2026", "numChildren": 1 }, "data": { "key": "KV3VRY6B", "version": 917, "itemType": "journalArticle", "title": "Spaceborne SAR Time-Series Radiometric Cross-Calibration via Spatio-Temporal Screening-Regression-Modeling Optimization", "creators": [ { "creatorType": "author", "firstName": "Y.", "lastName": "Zhou" }, { "creatorType": "author", "firstName": "J.", "lastName": "Su" }, { "creatorType": "author", "firstName": "L.", "lastName": "Ma" }, { "creatorType": "author", "firstName": "Q.", "lastName": "Yin" }, { "creatorType": "author", "firstName": "F.", "lastName": "Zhang" } ], "abstractNote": "Maintaining temporal radiometric consistency in synthetic aperture radar (SAR) satellite imagery requires advanced time-series radiometric calibration. Conventional approaches that rely on artificial calibration targets incur high operational costs. Capitalizing on the cost-efficiency of natural-target-based radiometric cross-calibration, this study extends cross-calibration principles to time-series calibration through three innovations: (1) A multi-criterion calibration target screening method through integrated analysis combining satellite revisit frequencies, target spatial histogram characteristics, and temporal scattering stability to overcome spatio-temporal constraints. (2) An enhanced calibration constant calculation approach that iteratively applies robust linear regression and removal of spatial pixel outliers to improve radiometric accuracy. (3) An inter-temporal calibration constant optimization mechanism by implementing Kalman filtering and sensor-attenuation modeling to ensure long-term stability. Experimental validation using Sentinel-1 data reveals that the maximum root mean square error (RMSE) across 69 temporal points is 0.36 dB, representing a 62% reduction compared to conventional methods. Furthermore, the Kalman-filtered results achieve a temporal stability of 0.0269 dB, an 89% improvement over unprocessed calibrations. This methodology enables continuous monitoring of SAR sensor performance with improved temporal consistency, which is crucial for the long-term harmonization of radiometric data. © 1980-2012 IEEE.", "publicationTitle": "IEEE Transactions on Geoscience and Remote Sensing", "publisher": "", "place": "", "date": "2026", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1109/TGRS.2026.3652214", "citationKey": "", "url": "https://www.scopus.com/inward/record.uri?eid=2-s2.0-105027964403&doi=10.1109%2FTGRS.2026.3652214&partnerID=40&md5=58f4234ca8972ca29492dd817532f16b", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "Scopus", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Calibration" }, { "tag": "Calibration constants" }, { "tag": "Calibration targets" }, { "tag": "Convergence of numerical methods" }, { "tag": "Cross calibration" }, { "tag": "Iterative methods" }, { "tag": "Kalman filter" }, { "tag": "Kalman filters" }, { "tag": "Linear regression" }, { "tag": "Mean square error" }, { "tag": "Radar imaging" }, { "tag": "Radiometric calibrations" }, { "tag": "Radiometric cross-calibration" }, { "tag": "Radiometry" }, { "tag": "Robust regressions" }, { "tag": "Screening" }, { "tag": "Space-based radar" }, { "tag": "Spaceborne synthetic aperture radars" }, { "tag": "Synthetic aperture radar" }, { "tag": "Time series" }, { "tag": "Time series analysis" }, { "tag": "Time-series calibration" }, { "tag": "Times series" }, { "tag": "cross-calibration" }, { "tag": "radiometric calibration" }, { "tag": "robust regression" }, { "tag": "synthetic aperture radar (SAR)" }, { "tag": "time-series calibration" } ], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "U46XP5KZ", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/U46XP5KZ", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/U46XP5KZ", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Luo et al.", "parsedDate": "2026", "numChildren": 1 }, "data": { "key": "U46XP5KZ", "version": 917, "itemType": "journalArticle", "title": "A geometric Cross-Propagation-Calibration method for SAR constellation based on the graph theory", "creators": [ { "creatorType": "author", "firstName": "Y.", "lastName": "Luo" }, { "creatorType": "author", "firstName": "X.", "lastName": "Qiu" }, { "creatorType": "author", "firstName": "B.", "lastName": "Lin" }, { "creatorType": "author", "firstName": "Z.", "lastName": "Jiao" }, { "creatorType": "author", "firstName": "W.", "lastName": "Wang" }, { "creatorType": "author", "firstName": "C.", "lastName": "Ding" } ], "abstractNote": "The networking capability of SAR constellations can effectively reduce the average revisit period, which has become a new trend in SAR Earth observation. However, the system electronic delay of several or even dozens of SAR satellites in a constellation must be calibrated and monitored for a long time to ensure high geometric accuracy of the product. In this paper, a geometric cross-propagation-calibration method for SAR constellations is proposed, which can calibrate the slant ranges of the SAR satellites in a constellation without any calibrators. The proposed method constructs a graph from all reference and uncalibrated SAR images involved in a cross-calibration task. For each uncalibrated image, the cumulative calibration error along paths originating from the reference images is estimated, enabling the identification of a path that minimizes this error. Cross-calibration is then performed sequentially along this optimal path. A closed-form expression is derived to estimate the cumulative calibration error along any path, which also reveals the underlying mechanism of error propagation in cross-calibration. Experiments based on real data show that the proposed method enables two China's microsatellites, Qilu-1 and Xingrui-9, to achieve geometric accuracy of less than 5 m after calibration. © 2026 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS)", "publicationTitle": "ISPRS Journal of Photogrammetry and Remote Sensing", "publisher": "", "place": "", "date": "2026", "volume": "233", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "346-359", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1016/j.isprsjprs.2026.01.007", "citationKey": "", "url": "https://www.scopus.com/inward/record.uri?eid=2-s2.0-105028991013&doi=10.1016%2Fj.isprsjprs.2026.01.007&partnerID=40&md5=160cd48b57ec84b60e1b4420ff9e6bc1", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "Scopus", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Calibration" }, { "tag": "Calibration error" }, { "tag": "Calibration method" }, { "tag": "China" }, { "tag": "Cross calibration" }, { "tag": "Earth" }, { "tag": "Earth observations" }, { "tag": "Error propagation" }, { "tag": "Errors" }, { "tag": "Geometric accuracy" }, { "tag": "Geometric calibration" }, { "tag": "Geometric calibrations" }, { "tag": "Geometry" }, { "tag": "Graph theory" }, { "tag": "Micro satellites" }, { "tag": "Positioning" }, { "tag": "Radar imaging" }, { "tag": "Remote sensing" }, { "tag": "SAR constellation" }, { "tag": "Space applications" }, { "tag": "Space optics" }, { "tag": "Space-based radar" }, { "tag": "Spaceborne synthetic aperture radar" }, { "tag": "Spaceborne synthetic aperture radars" }, { "tag": "Synthetic aperture radar" }, { "tag": "calibration" }, { "tag": "error analysis" }, { "tag": "image processing" }, { "tag": "networking" }, { "tag": "positioning system" }, { "tag": "satellite constellation" }, { "tag": "synthetic aperture radar" } ], "collections": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "PGNKBJPD", "version": 917, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/PGNKBJPD", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/PGNKBJPD", "type": "text/html" }, "up": { "href": "https://api.zotero.org/groups/538513/items/KV3VRY6B", "type": "application/json" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "numChildren": 0 }, "data": { "key": "PGNKBJPD", "version": 917, "parentItem": "KV3VRY6B", "itemType": "note", "note": "

Export Date: 09 February 2026; Cited By: 0

", "tags": [], "relations": {}, "dateAdded": "2026-02-27T12:26:55Z", "dateModified": "2026-02-27T12:26:55Z" } }, { "key": "ISCHG424", "version": 916, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/ISCHG424", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/ISCHG424", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Chen et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "ISCHG424", "version": 916, "itemType": "journalArticle", "title": "A global long-term (2002–2022) C-band vegetation optical depth record retrieved after merging AMSR-E, AMSR2 and WindSat", "creators": [ { "creatorType": "author", "firstName": "Dongbo", "lastName": "Chen" }, { "creatorType": "author", "firstName": "Lei", "lastName": "Fan" }, { "creatorType": "author", "firstName": "Jian", "lastName": "Peng" }, { "creatorType": "author", "firstName": "Gabrielle De", "lastName": "Lannoy" }, { "creatorType": "author", "firstName": "Jean-Pierre", "lastName": "Wigneron" }, { "creatorType": "author", "firstName": "Frédéric", "lastName": "Frappart" }, { "creatorType": "author", "firstName": "Shengli", "lastName": "Tao" }, { "creatorType": "author", "firstName": "Mengjia", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Xiaojun", "lastName": "Li" }, { "creatorType": "author", "firstName": "Xiangzhuo", "lastName": "Liu" }, { "creatorType": "author", "firstName": "Huan", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Qiangqiang", "lastName": "Yuan" }, { "creatorType": "author", "firstName": "Xiuzhi", "lastName": "Chen" }, { "creatorType": "author", "firstName": "Yao", "lastName": "Xiao" }, { "creatorType": "author", "firstName": "Philippe", "lastName": "Ciais" } ], "abstractNote": "Vegetation optical depth (VOD) based on microwave remote sensing has become an essential indicator for monitoring large-scale vegetation conditions. The relatively long-term record of satellite-based passive C-band observations offers the potential for assessing dynamic vegetation changes. Due to the limited operational lifetime of individual microwave sensors, retrieving a long-term C-band VOD (C-VOD) dataset often requires combining multiple sensors, such as Advanced Microwave Scanning Radiometer for EOS Aqua (AMSR-E, 2002–2011), Advanced Microwave Scanning Radiometer 2 (AMSR2, 2012–present) and WindSat (2003–2020). Retrieving a long-term C-VOD from their C-band brightness temperature (TB) observations faces two major challenges: (i) non-negligible systematic biases exist between the TB observations among the three sensors; (ii) TB from different sensors may not be strongly associated, especially in tropical forests with small seasonal variations. To address these challenges, we employed a combined inter-calibration method, using linear regression in sparse vegetation and linear rescaling in dense vegetation, to merge TB from three sensors. Results showed that: (i) in undisturbed dense forests where minimal emissivity variation can be assumed, the merged TB (2002–2022) exhibited strong temporal correlations with skin temperature (H polarization: R = 0.90, V polarization: R = 0.86); (ii) the merged C-VOD retrieved from the merged TB exhibited substantially improved temporal consistency across three sensors, reducing global discrepancies between AMSR-E and AMSR2 from 6.20 % to 0.34 %. Furthermore, the merged C-VOD showed stable long-term consistency across sensors, with paired t-tests indicating no significant differences (P-value > 0.01) at the global and vegetation-type scales, confirming reliable cross-sensor continuity; (iii) the merged C-VOD showed stronger temporal correlations with normalized difference vegetation index, enhanced vegetation index, and site-level gross primary production across more vegetated areas globally, and exhibited higher and more stable spatial correlations with vegetation variables across sensor transitions compared to the existing merged C-VOD product. © 2025", "publicationTitle": "International Journal of Applied Earth Observation and Geoinformation", "publisher": "Elsevier B.V.", "place": "", "date": "2025", "volume": "145", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Int. J. Appl. Earth Obs. Geoinformation", "DOI": "10.1016/j.jag.2025.104961", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "1569-8432", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "English", "libraryCatalog": "Scopus", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "YAF676DI", "version": 916, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/YAF676DI", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/YAF676DI", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Moradi and Kalluri", "parsedDate": "2025-11", "numChildren": 0 }, "data": { "key": "YAF676DI", "version": 916, "itemType": "journalArticle", "title": "ML-driven cross-calibration of microwave and infrared instruments", "creators": [ { "creatorType": "author", "firstName": "Isaac", "lastName": "Moradi" }, { "creatorType": "author", "firstName": "Satya", "lastName": "Kalluri" } ], "abstractNote": "Microwave (MW) and infrared (IR) observations are fundamental for weather forecasting, climate monitoring, and atmospheric sounding. Traditionally, inter-calibration efforts have focused on harmonizing measurements between similar instruments or within the same spectral domain. In this study, we explore the use of machine learning (ML) to directly cross-calibrate MW and IR observations, leveraging data from the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) onboard the NOAA-20 (N20) and Suomi-NPP (NPP) satellites. We demonstrate that an ML-model trained using CrIS observations as input (2211 channels) can predict the ATMS observations (22 channels) with a bias less than 0.1 K and a the coefficients of determination generally greater than 90%. Our results highlight the potential of ML-based cross-calibration approaches for bridging instruments across different spectral regions, provided that the input observations contain all necessary information to reconstruct the target observations. The proposed methodology offers a path forward for the cross-calibration of instruments operating in different spectral domains.", "publicationTitle": "Machine Learning: Earth", "publisher": "IOP Publishing", "place": "", "date": "2025-11", "volume": "1", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "015012", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Mach. Learn.: Earth", "DOI": "10.1088/3049-4753/ae1cce", "citationKey": "", "url": "https://doi.org/10.1088/3049-4753/ae1cce", "accessDate": "2025-11-28T15:14:17Z", "PMID": "", "PMCID": "", "ISSN": "3049-4753", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Institute of Physics", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "FFNPFYPE", "version": 916, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/FFNPFYPE", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/FFNPFYPE", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Zhao et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "FFNPFYPE", "version": 916, "itemType": "journalArticle", "title": "Cross-Calibrated FY-4A and GOES-15 Data for >2 MeV Electron Flux Prediction at Geosynchronous Orbit: A Machine Learning Approach", "creators": [ { "creatorType": "author", "firstName": "Yibo", "lastName": "Zhao" }, { "creatorType": "author", "firstName": "Song", "lastName": "Fu" }, { "creatorType": "author", "firstName": "Xianguo", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Binbin", "lastName": "Ni" }, { "creatorType": "author", "firstName": "Li", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Weixin", "lastName": "Chen" }, { "creatorType": "author", "firstName": "Xiaotong", "lastName": "Yun" }, { "creatorType": "author", "firstName": "Yuan", "lastName": "Lei" }, { "creatorType": "author", "firstName": "Xin", "lastName": "Ma" }, { "creatorType": "author", "firstName": "Guohong", "lastName": "Shen" }, { "creatorType": "author", "firstName": "Jianhang", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Kunkun", "lastName": "Xia" }, { "creatorType": "author", "firstName": "Rui", "lastName": "Feng" }, { "creatorType": "author", "firstName": "Qiongyue", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Xiangyuan", "lastName": "Tong" } ], "abstractNote": "High-energy electrons in Earth's outer radiation belt pose a significant threat to orbiting spacecraft, accurately forecasting these fluxes is crucial for mitigating potential damage. Therefore, it is necessary to fuse data from different satellites to eliminate systematic discrepancies between satellite data sets, thereby enabling the development of more accurate and reliable predictive models. This study presents a cross-satellite calibration method to address systematic discrepancies in >2 MeV electron flux measurements from the FY-4A and GOES-15 satellites. By aligning magnetic local times (MLT) through a time-shift operation and excluding solar proton contaminations, we ensure high-quality data for calibration. The data are divided into 24 MLT intervals to determine optimal calibration factors, significantly improving consistency between the two data sets. Using the calibrated data, we generate a merged data set spanning 13 years, encompassing a complete solar activity cycle. This extended data set is utilized to develop a neural network-based nowcasting model for predicting >2 MeV electron integral flux at geosynchronous orbit (GEO). Our results demonstrate that cross-calibration with expanding the data set's temporal coverage enhances predictive performance for both quiet and active geomagnetic periods. The improved accuracy arises from increased training data volume, comprehensive representation of solar activity cycles. These findings underscore the importance of cross-satellite calibration and long-term data sets for advancing space weather forecasting capabilities. This study highlights the value of multi-source data integration and advanced modeling techniques in understanding and mitigating radiation belt hazards. © 2025 The Author(s).", "publicationTitle": "Space Weather", "publisher": "John Wiley and Sons Inc", "place": "", "date": "2025", "volume": "23", "issue": "11", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Space Weather", "DOI": "10.1029/2025SW004419", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "1542-7390", "archive": "", "archiveLocation": "", "shortTitle": "Cross-Calibrated FY-4A and GOES-15 Data for >2 MeV Electron Flux Prediction at Geosynchronous Orbit", "language": "English", "libraryCatalog": "Scopus", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "AJNSH593", "version": 916, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/AJNSH593", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/AJNSH593", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Gurev et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "AJNSH593", "version": 916, "itemType": "journalArticle", "title": "Cross-Calibration of Energetic Electron Flux Measurements From the Cluster and THEMIS Missions", "creators": [ { "creatorType": "author", "firstName": "Dmitrii", "lastName": "Gurev" }, { "creatorType": "author", "firstName": "Elena A.", "lastName": "Kronberg" }, { "creatorType": "author", "firstName": "Andrei", "lastName": "Runov" }, { "creatorType": "author", "firstName": "Yuri", "lastName": "Shprits" } ], "abstractNote": "Energetic electrons in Earth's magnetosphere play a critical role in space weather processes and pose risks to spacecraft electronics. Combining measurements from multiple missions, such as Cluster and Time History of Events and Macroscale Interactions during Substorms (THEMIS), enhances our understanding of these populations but requires cross-calibration due to instrumental differences. This study presents a statistical comparison of (Formula presented.) 40–400 keV electron flux measurements from Cluster/Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) and THEMIS/Solid State Telescope (SST) over 2007–2018. By analyzing the statistical distance between local flux distributions, we quantify discrepancies between the data sets and derive cross-calibration factors, covering radial distances up to 16 (Formula presented.). Our results show that SST fluxes consistently exceed IES observations, with the difference increasing with energy. The derived correction factors enable the joint use of the Cluster and THEMIS energetic electron data for multipoint space weather studies. © 2025. The Author(s).", "publicationTitle": "Journal of Geophysical Research: Space Physics", "publisher": "John Wiley and Sons Inc", "place": "", "date": "2025", "volume": "130", "issue": "10", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "J. Geophys. Res. Space Phys.", "DOI": "10.1029/2025JA034226", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2169-9380", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "English", "libraryCatalog": "Scopus", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "VG8D3F47", "version": 910, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/VG8D3F47", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/VG8D3F47", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Gu et al.", "parsedDate": "2025-10", "numChildren": 0 }, "data": { "key": "VG8D3F47", "version": 910, "itemType": "journalArticle", "title": "Singular Spectrum Analysis to Correct the Seasonal Variation in the FCDR of FY-3A/B/C VIRR Reflective Solar Bands", "creators": [ { "creatorType": "author", "firstName": "Z", "lastName": "Gu" }, { "creatorType": "author", "firstName": "L", "lastName": "Chen" }, { "creatorType": "author", "firstName": "L", "lastName": "Sun" }, { "creatorType": "author", "firstName": "RH", "lastName": "Wu" }, { "creatorType": "author", "firstName": "H", "lastName": "Qiu" }, { "creatorType": "author", "firstName": "N", "lastName": "Xu" }, { "creatorType": "author", "firstName": "P", "lastName": "Zhang" } ], "abstractNote": "The Visible and Infrared Radiometer (VIRR) onboard China's Fengyun-3A/B/C (FY-3A/B/C) satellites has delivered essential global Earth observations for over 15 years, enabling critical applications in cloud dynamics research, vegetation assessment, and environmental monitoring. However, VIRR lacks onboard calibration systems for its visible/near-infrared channels, which results in progressive radiometric degradation due to cumulative space radiation and detector aging, challenging the generation of stable long-term climate datasets [e.g., the fundamental climate data record (FCDR)]. By integrating simultaneous nadir overpass (SNO) cross-calibration technique with references from Aqua's Moderate Resolution Imaging Spectroradiometer (MODIS), we identified pronounced seasonal fluctuations in long-term recalibration coefficients, particularly for the 0.86 mu m. To isolate these effects, singular spectrum analysis (SSA) was used to decompose the coefficient series into three components: trend, seasonal fluctuations, and residuals. A hybrid calibration model was then formulated by integrating the isolated trend and seasonal features. Validation across globally distributed pseudo-invariant sites confirmed enhanced radiometric stability. The work highlights the necessity of accounting for seasonally modulated calibration artifacts, which were previously unaddressed in operational protocols, to ensure the stability and accuracy of climate data records (CDRs).", "publicationTitle": "JOURNAL OF METEOROLOGICAL RESEARCH", "publisher": "", "place": "", "date": "2025 OCT", "volume": "39", "issue": "5", "section": "", "partNumber": "", "partTitle": "", "pages": "1330-1345", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1007/s13351-025-4244-9", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2095-6037", "archive": "", "archiveLocation": "WOS:001613992700012", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "DMSIZVGU", "version": 910, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/DMSIZVGU", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/DMSIZVGU", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Wang et al.", "parsedDate": "2025-10-21", "numChildren": 0 }, "data": { "key": "DMSIZVGU", "version": 910, "itemType": "journalArticle", "title": "Extending AVHRR Climate Data Records into the VIIRS Era for Polar Climate Research", "creators": [ { "creatorType": "author", "firstName": "XJ", "lastName": "Wang" }, { "creatorType": "author", "firstName": "JR", "lastName": "Key" }, { "creatorType": "author", "firstName": "S", "lastName": "Moeller" }, { "creatorType": "author", "firstName": "RJ", "lastName": "Dworak" }, { "creatorType": "author", "firstName": "X", "lastName": "Shao" }, { "creatorType": "author", "firstName": "KR", "lastName": "Knapp" } ], "abstractNote": "Highlights What are the main findings? A statistical method for intercalibrating VIIRS bands to AVHRR channels allows for the use of previously developed AVHRR algorithms with VIIRS data. Two existing AVHRR climate data records are now being continued with VIIRS: the Polar Pathfinder Fundamental Climate Data Record (FCDR) and the Polar Pathfinder Extended Thematic Climate Data Record (TCDR). The TCDR provides high latitude surface properties, cloud characteristics, and the radiation budget. What are the implication of the main finding? Combining AVHRR and VIIRS data into long-term, continuous, consistent, and traceable CDRs provides the fundamental tools for monitoring the polar environment, its weather, and climate. The use of the original AVHRR Polar Pathfinder CDRs has resulted in many discoveries about polar climate trends and interactions. Extending the time series with VIIRS will allow the scientific community to continue polar climate research with these products well into the future.Highlights What are the main findings? A statistical method for intercalibrating VIIRS bands to AVHRR channels allows for the use of previously developed AVHRR algorithms with VIIRS data. Two existing AVHRR climate data records are now being continued with VIIRS: the Polar Pathfinder Fundamental Climate Data Record (FCDR) and the Polar Pathfinder Extended Thematic Climate Data Record (TCDR). The TCDR provides high latitude surface properties, cloud characteristics, and the radiation budget. What are the implication of the main finding? Combining AVHRR and VIIRS data into long-term, continuous, consistent, and traceable CDRs provides the fundamental tools for monitoring the polar environment, its weather, and climate. The use of the original AVHRR Polar Pathfinder CDRs has resulted in many discoveries about polar climate trends and interactions. Extending the time series with VIIRS will allow the scientific community to continue polar climate research with these products well into the future.Abstract The Advanced Very High-Resolution Radiometer (AVHRR) onboard NOAA-7 through NOAA-19 satellites has been the primary data source for two Climate Data Records (CDRs) that were developed specifically for Arctic and Antarctic studies: the AVHRR Polar Pathfinder (APP) and Extended AVHRR Polar Pathfinder (APP-x). With the decommissioning of these satellites and the loss of the AVHRR, a method for extending the CDRs with the Visible Infrared Imaging Radiometer Suite (VIIRS) on NOAA's recent satellites is presented. The goal is to produce long-term, continuous, consistent, and traceable CDRs for polar climate research. As a result, APP and APP-x can now be continued as the VIIRS Polar Pathfinder (VPP) and Extended VIIRS Polar Pathfinder (VPP-x) CDRs. To ensure consistency, a VIIRS Global Area Coverage (VGAC) dataset that is comparable to AVHRR GAC data was used to develop an analogous VIIRS Polar Pathfinder suite. Five VIIRS bands (I1, I2, M12, M15, and M16) were selected to correspond to AVHRR Channels 1, 2, 3b, 4, and 5, respectively. A multivariate regression approach was used to intercalibrate these VIIRS bands to AVHRR channels based on data from overlapping AVHRR and VIIRS observations from 2013 to 2018. The data from 2012 and 2019 were reserved for independent validation. For the Arctic region north of 60 degrees N at 14:00/04:00 Local Solar Time (LST) during 2012-2019, mean biases between APP and VPP composites at a spatial resolution of 5 km are -0.85%/3.03% (Channel 1), -1.22%/3.65% (Channel 2), -0.18 K/0.81 K (Channel 3b), 0.01 K/0.\n24 K (Channel 4), and 0.07 K/0.19 K (Channel 5). Mean biases between APP-x and VPP-x at a spatial resolution of 25 km for the same region and period are -1.52%/-1.48% for surface broadband albedo, 0.69 K/0.61 K for surface skin temperature, and -0.011 m/-0.017 m for sea ice thickness. Similar results were observed for the Antarctic region south of 60 degrees S at 14:00/02:00 LST, indicating strong agreement between APP and VPP, and between APP-x and VPP-x.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2025 OCT 21", "volume": "17", "issue": "20", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs17203495", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001602901000001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "PMXGP3ZF", "version": 910, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/PMXGP3ZF", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/PMXGP3ZF", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Zeng et al.", "parsedDate": "2025-10-28", "numChildren": 0 }, "data": { "key": "PMXGP3ZF", "version": 910, "itemType": "journalArticle", "title": "Radiometric Cross-Calibration and Performance Analysis of HJ-2A/2B 16m-MSI Using Landsat-8/9 OLI with Spectral-Angle Difference Correction", "creators": [ { "creatorType": "author", "firstName": "J", "lastName": "Zeng" }, { "creatorType": "author", "firstName": "H", "lastName": "Zhao" }, { "creatorType": "author", "firstName": "YF", "lastName": "Su" }, { "creatorType": "author", "firstName": "QQ", "lastName": "Lan" }, { "creatorType": "author", "firstName": "QJ", "lastName": "Han" }, { "creatorType": "author", "firstName": "XW", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "XM", "lastName": "Wang" }, { "creatorType": "author", "firstName": "ZP", "lastName": "Xu" }, { "creatorType": "author", "firstName": "ZH", "lastName": "Hu" }, { "creatorType": "author", "firstName": "XZ", "lastName": "Du" }, { "creatorType": "author", "firstName": "BP", "lastName": "Yang" } ], "abstractNote": "Highlights What are the main findings? Developed a novel cross-calibration method for HJ-2A/2B, incorporating observation-angle and spectral band adjustment corrections. Achieved high radiometric consistency, with cross-calibration results within 10% of official values and inter-sensor differences below 3%. What are the implications of the main findings? Enables frequent radiometric monitoring, overcoming the major limitation of traditional vicarious calibration. Provides a reliable solution for long-term data quality assurance, enhancing the reliability of HJ-2A/2B data for environmental applications.Highlights What are the main findings? Developed a novel cross-calibration method for HJ-2A/2B, incorporating observation-angle and spectral band adjustment corrections. Achieved high radiometric consistency, with cross-calibration results within 10% of official values and inter-sensor differences below 3%. What are the implications of the main findings? Enables frequent radiometric monitoring, overcoming the major limitation of traditional vicarious calibration. Provides a reliable solution for long-term data quality assurance, enhancing the reliability of HJ-2A/2B data for environmental applications.Abstract The Huanjing-2A/2B (HJ-2A/2B) satellites are China's next-generation environmental monitoring satellites, equipped with four visible light wide-swath charge-coupled device (CCD) sensors. These sensors enable the acquisition of 16-m multispectral imagery (16m-MSI) with a swath width of 800 km through field-of-view stitching. However, traditional vicarious calibration techniques are limited by their calibration frequency, making them insufficient for continuous monitoring requirements. To address this challenge, the present study proposes a spectral-angle difference correction-based cross-calibration approach, using the Landsat 8/9 Operational Land Imager (OLI) as the reference sensor to calibrate the HJ-2A/2B CCD sensors. This method improves both radiometric accuracy and temporal frequency. The study utilizes cloud-free image pairs of HJ-2A/2B CCD and Landsat 8/9 OLI, acquired simultaneously at the Dunhuang and Golmud calibration sites between 2021 and 2024, in combination with atmospheric parameters from the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) dataset and historical ground-measured spectral reflectance data for cross-calibration. The methodology includes spatial matching and resampling of the image pairs, along with the identification of radiometrically stable homogeneous regions. To account for sensor viewing geometry differences, an observation-angle linear correction model is introduced. Spectral band adjustment factors (SBAFs) are also applied to correct for discrepancies in spectral response functions (SRFs) across sensors. Experimental results demonstrate that the cross-calibration coefficients differ by less than 10% compared to vicarious calibration results from the China Centre for Resources Satellite Data and Application (CRESDA). Additionally, using Sentinel-2 MSI as the reference sensor, the cross-calibration coefficients were independently validated through cross-validation. The results indicate that the radiometrically corrected HJ-2A/2B 16m-MSI CCD data, based on these coefficients, exhibit improved radiometric consistency with Sentinel-2 MSI observations.\nFurther analysis shows that the cross-calibration method significantly enhances radiometric consistency across the HJ-2A/2B 16m-MSI CCD sensors, with radiometric response differences between CCD1 and CCD4 maintained below 3%. Error analysis quantifies the impact of atmospheric parameters and surface reflectance on calibration accuracy, with total uncertainty calculated. The proposed spectral-angle correction-based cross-calibration method not only improves calibration accuracy but also offers reliable technical support for long-term radiometric performance monitoring of the HJ-2A/2B 16m-MSI CCD sensors.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2025 OCT 28", "volume": "17", "issue": "21", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs17213569", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001613129700001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "P6UU8IQN", "version": 910, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/P6UU8IQN", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/P6UU8IQN", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Zhu et al.", "parsedDate": "2025-10-28", "numChildren": 0 }, "data": { "key": "P6UU8IQN", "version": 910, "itemType": "journalArticle", "title": "In-Flight Radiometric Calibration of Gas Absorption Bands for the Gaofen-5 (02) DPC Using Sunglint", "creators": [ { "creatorType": "author", "firstName": "SF", "lastName": "Zhu" }, { "creatorType": "author", "firstName": "LG", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "YQ", "lastName": "Xie" }, { "creatorType": "author", "firstName": "LL", "lastName": "Qie" }, { "creatorType": "author", "firstName": "ZQ", "lastName": "Li" }, { "creatorType": "author", "firstName": "MM", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "XC", "lastName": "Wang" } ], "abstractNote": "The Directional Polarimetric Camera (DPC) onboard the Gaofen-5 (02) satellite includes gas absorption bands that are crucial for the quantitative retrieval of clouds, atmospheric aerosols, and surface parameters. However, in-flight radiometric calibration of these bands remains challenging due to strong absorption features and the lack of onboard calibration devices. In this study, a calibration method that exploits functional relationships between the reflectance ratios of gas absorption and adjacent reference bands and key surface-atmosphere parameters over sunglint were presented. Radiative transfer simulations were combined with polynomial fitting to establish these relationships, and prior knowledge of surface pressure and water vapor column concentration was incorporated to achieve high-precision calibration. Results show that the calibration uncertainty of the oxygen absorption band is mainly driven by surface pressure, with a total uncertainty of 3.01%. For the water vapor absorption band, uncertainties are primarily associated with water vapor column concentration and surface reflectance, yielding total uncertainties of 3.45%. Validation demonstrates the robustness of the proposed method: (1) cross-calibration using desert samples confirms the stability of the results, and (2) the retrieved surface pressure agrees with the DEM-derived estimates, and the retrieved total column water vapor agrees with the MODIS products, confirming the calibration. Overall, the method provides reliable in-flight calibration of DPC gas absorption bands on Gaofen-5 (02) and can be adapted to similar sensors with comparable spectral configurations.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2025 OCT 28", "volume": "17", "issue": "21", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs17213558", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001615403600001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-11-28T15:14:44Z", "dateModified": "2025-11-28T15:14:44Z" } }, { "key": "S2QEQ84J", "version": 916, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/S2QEQ84J", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/S2QEQ84J", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Ni et al.", "parsedDate": "2026", "numChildren": 0 }, "data": { "key": "S2QEQ84J", "version": 916, "itemType": "journalArticle", "title": "CSFAFormer: Category-selective feature aggregation transformer for multimodal remote sensing image semantic segmentation", "creators": [ { "creatorType": "author", "firstName": "Yue", "lastName": "Ni" }, { "creatorType": "author", "firstName": "Donglin", "lastName": "Xue" }, { "creatorType": "author", "firstName": "Weijian", "lastName": "Chi" }, { "creatorType": "author", "firstName": "Ji", "lastName": "Luan" }, { "creatorType": "author", "firstName": "Jiahang", "lastName": "Liu" } ], "abstractNote": "Feature fusion is one of the keys to multimodal data segmentation. Different fusion mechanisms vary significantly in how effectively they utilize inter-modal features, exploit complementary information, and enhance representations, while also greatly affecting model parameters and computational complexity. Cross-attention fusion mechanism (CAFM) is the most widely used feature fusion mechanism in the current multimodal fusion classification task, but due to the inherent limitation, it cannot adapt to the differentiated feature requirements of different classes and leads to the blurring of interclass and dispersal features of intraclass. To address these challenges, a novel Category-Selective Feature Aggregation Transformer (CSFAFormer) is proposed to dynamically adjust the interaction weights between modalities along the class dimension, thereby fully leveraging the complementary advantages of different modalities. To accommodate the differentiated needs of different categories, a Category Cross-Calibration Mechanism (C3M) is designed to compress multi-channel features, estimate pixel-level class distributions, and employ a confidence-based cross-calibration strategy to dynamically adjust interaction weights along the class dimension, better accommodating the varying demands of different classes. To further semantic consistency and inter-class separability, a Category-Selective Transformer Module is proposed to leverage the class information calibrated by C3M for adaptive weighted fusion along the class dimension, thereby optimizing the representation of category-specific features. Experimental results indicate that CSFAFormer significantly outperforms in segmentation performance. Compared to the CAFM, CSFAFormer reduces the parameter count by 38.5 % and the computational cost by 72.3 %, while maintaining superior performance. The code is available at: https://github.com/NUAALISILab/CSFAFormer. © 2025", "publicationTitle": "Information Fusion", "publisher": "Elsevier B.V.", "place": "", "date": "2026", "volume": "127", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Inf. Fusion", "DOI": "10.1016/j.inffus.2025.103786", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "1566-2535", "archive": "", "archiveLocation": "", "shortTitle": "CSFAFormer", "language": "English", "libraryCatalog": "Scopus", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-10-31T10:28:03Z", "dateModified": "2025-10-31T10:28:03Z" } }, { "key": "GC8XWY86", "version": 909, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/GC8XWY86", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/GC8XWY86", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "An et al.", "parsedDate": "2025-10-02", "numChildren": 0 }, "data": { "key": "GC8XWY86", "version": 909, "itemType": "journalArticle", "title": "Comparative Evaluation of SNO and Double Difference Calibration Methods for FY-3D MERSI TIR Bands Using MODIS/Aqua as Reference", "creators": [ { "creatorType": "author", "firstName": "SF", "lastName": "An" }, { "creatorType": "author", "firstName": "FZ", "lastName": "Weng" }, { "creatorType": "author", "firstName": "XZ", "lastName": "Han" }, { "creatorType": "author", "firstName": "CZ", "lastName": "Ye" } ], "abstractNote": "Radiometric consistency across satellite platforms is fundamental to producing high-quality Climate Data Records (CDRs). Because different cross-calibration methods have distinct advantages and limitations, comparative evaluation is necessary to ensure record accuracy. This study presents a comparative assessment of two widely applied calibration approaches-Simultaneous Nadir Overpass (SNO) and Double Difference (DD)-for the thermal infrared (TIR) bands of FY-3D MERSI. MODIS/Aqua serves as the reference sensor, while radiative transfer simulations driven by ERA5 inputs are generated with the Advanced Radiative Transfer Modeling System (ARMS) to support the analysis. The results show that SNO performs effectively when matchup samples are sufficiently large and globally representative but is less applicable under sparse temporal sampling or orbital drift. In contrast, the DD method consistently achieves higher calibration accuracy for MERSI Bands 24 and 25 under clear-sky conditions. It reduces mean biases from similar to-0.5 K to within +/- 0.1 K and lowers RMSE from similar to 0.6 K to 0.3-0.4 K during 2021-2022. Under cloudy conditions, DD tends to overcorrect because coefficients derived from clear-sky simulations are not directly transferable to cloud-covered scenes, whereas SNO remains more stable though less precise. Overall, the results suggest that the two methods exhibit complementary strengths, with DD being preferable for high-accuracy calibration in clear-sky scenarios and SNO offering greater stability across variable atmospheric conditions. Future work will validate both methods under varied surface and atmospheric conditions and extend their use to additional sensors and spectral bands.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2025 OCT 2", "volume": "17", "issue": "19", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs17193353", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001595050200001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-10-31T10:28:03Z", "dateModified": "2025-10-31T10:28:03Z" } }, { "key": "ZFUTYPYE", "version": 909, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/ZFUTYPYE", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/ZFUTYPYE", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Choi et al.", "parsedDate": "2025-09-24", "numChildren": 0 }, "data": { "key": "ZFUTYPYE", "version": 909, "itemType": "journalArticle", "title": "Radiometric Cross-Calibration and Validation of KOMPSAT-3/AEISS Using Sentinel-2A/MSI", "creators": [ { "creatorType": "author", "firstName": "JH", "lastName": "Choi" }, { "creatorType": "author", "firstName": "KW", "lastName": "Jin" }, { "creatorType": "author", "firstName": "DH", "lastName": "Cha" }, { "creatorType": "author", "firstName": "KB", "lastName": "Choi" }, { "creatorType": "author", "firstName": "YH", "lastName": "Jo" }, { "creatorType": "author", "firstName": "KN", "lastName": "Kim" }, { "creatorType": "author", "firstName": "GB", "lastName": "Kang" }, { "creatorType": "author", "firstName": "HY", "lastName": "Shin" }, { "creatorType": "author", "firstName": "JY", "lastName": "Lee" }, { "creatorType": "author", "firstName": "E", "lastName": "Kim" }, { "creatorType": "author", "firstName": "H", "lastName": "Chang" }, { "creatorType": "author", "firstName": "YG", "lastName": "Lee" } ], "abstractNote": "Highlights What are the main findings? Cross-calibration with Sentinel-2A/MSI, applying SBAF and BRDF corrections, yielded gains of 0.0196 (Blue), 0.0237 (Green), 0.0214 (Red), and 0.0136 (NIR), consistent with prior KOMPSAT-3 studies. Five vicarious calibration campaigns at the KARI site produced gains of 0.0217 (Blue), 0.0299 (Green), 0.0221 (Red), and 0.0155 (NIR), demonstrating consistency with earlier studies. What is the implication of the main finding? Both cross and vicarious calibration confirm that KOMPSAT-3/AEISS has maintained stable radiometric coefficients over more than a decade of operation. These traditional calibration results suggest the potential to extend toward emerging methodologies based on machine learning and deep learning.Highlights What are the main findings? Cross-calibration with Sentinel-2A/MSI, applying SBAF and BRDF corrections, yielded gains of 0.0196 (Blue), 0.0237 (Green), 0.0214 (Red), and 0.0136 (NIR), consistent with prior KOMPSAT-3 studies. Five vicarious calibration campaigns at the KARI site produced gains of 0.0217 (Blue), 0.0299 (Green), 0.0221 (Red), and 0.0155 (NIR), demonstrating consistency with earlier studies. What is the implication of the main finding? Both cross and vicarious calibration confirm that KOMPSAT-3/AEISS has maintained stable radiometric coefficients over more than a decade of operation. These traditional calibration results suggest the potential to extend toward emerging methodologies based on machine learning and deep learning.Abstract The successful launch of Korea Multipurpose Satellite-3/Advanced Earth Imaging Sensor System (KOMPSAT-3/AEISS) on 18 May 2012 allowed the Republic of Korea to meet the growing demand for high-resolution satellite imagery. However, like all satellite sensors, KOMPSAT-3/AEISS experienced temporal changes post-launch and thus requires ongoing evaluation and calibration. Although more than a decade has passed since launch, the KOMPSAT-3/AEISS mission and its multi-year data archive remain widely used. This study focused on the cross-calibration of KOMPSAT-3/AEISS with Sentinel-2A/Multispectral Instrument (MSI) by comparing the radiometric responses of the two satellite sensors under similar observation conditions, leveraging the linear relationship between Digital Numbers (DN) and top-of-atmosphere (TOA) radiance. Cross-calibration was performed using near-simultaneous satellite images of the same region, and the Spectral Band Adjustment Factor (SBAF) was calculated and applied to account for differences in spectral response functions (SRF). Additionally, Bidirectional Reflectance Distribution Function (BRDF) correction was applied using MODIS-based kernel models to minimize angular reflectance effects caused by differences in viewing and illumination geometry. This study aims to evaluate the radiometric consistency of KOMPSAT-3/AEISS relative to Sentinel-2A/MSI over Baotou scenes acquired in 2022-2023, derive band-specific calibration coefficients and compare them with prior results, and conduct a side-by-side comparison of cross-calibration and vicarious calibration. Furthermore, the cross-calibration yielded band-specific gains of 0.0196 (Blue), 0.0237 (Green), 0.0214 (Red), and 0.0136 (NIR). These findings offer valuable implications for Earth observation, environmental monitoring, and the planning and execution of future satellite missions.", "publicationTitle": "REMOTE SENSING", "publisher": "", "place": "", "date": "2025 SEP 24", "volume": "17", "issue": "19", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.3390/rs17193280", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2072-4292", "archive": "", "archiveLocation": "WOS:001593892000001", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-10-31T10:28:03Z", "dateModified": "2025-10-31T10:28:03Z" } }, { "key": "MW3GPQ4I", "version": 916, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/MW3GPQ4I", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/MW3GPQ4I", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Wang et al.", "parsedDate": "2025-08-22", "numChildren": 0 }, "data": { "key": "MW3GPQ4I", "version": 916, "itemType": "journalArticle", "title": "Understanding Overland Satellite-Based Precipitation Errors in IMERG Products as a Function of Input Sources", "creators": [ { "creatorType": "author", "firstName": "Jianxin", "lastName": "Wang" }, { "creatorType": "author", "firstName": "David B.", "lastName": "Wolff" }, { "creatorType": "author", "firstName": "Jackson", "lastName": "Tan" }, { "creatorType": "author", "firstName": "George J.", "lastName": "Huffman" } ], "abstractNote": "The multisatellite precipitation product from the U.S. Global Precipitation Measurement (GPM) mission Science Team, the Integrated Multi-satellitE Retrievals for GPM (IMERG), is a widely used GPM product. It merges precipitation retrievals from passive microwave (PMW) and infrared (IR) sensors on board a collection of satellites operated by several agencies around the globe. IMERG retrospectively provides over two decades’ global precipitation data at fine temporal–spatial resolutions. This overland study evaluates the satellite-based precipitation statistics in the latest versions of the IMERG (V06B and V07B) products over the conterminous United States. High-resolution, ground-based radar precipitation estimates from a quality-controlled version of the Multi-Radar Multi-Sensor system—developed under the GPM Ground Validation effort—are used as the reference product. The relative performance of the two IMERG versions is evaluated using volumetric and categorical statistical metrics. The precipitation retrieval errors are further separated into three individual components: hit bias, missed-precipitation bias, and false-precipitation bias, and all are traced back to the sensor-specific sources, as well as different levels of the IR input usage. The evaluation highlights the clear improvement in the IMERG V07B precipitation product for all seasons, especially for winter, with reduced systematic bias and uncertainty and increased precipitation detectability in comparison with V06B. The changes in V07B include the use of input data processed with improved algorithms for both PMW and IR retrievals, the addition of PMW retrievals over frozen surfaces, and upgrades in the intercalibration that address sources of bias in V06B. Significance Statement This study conducts the first extensive evaluation of IMERG V07B against V06B at their native resolutions using ground-based radar data over the conterminous United States (CONUS) and traces errors in the IMERG products back to specific sensors and the use of infrared data. The results indicate that the changes in V07B clearly improved the performance of the IMERG estimates, with reduced systematic bias and uncertainty and improved precipitation detection.", "publicationTitle": "", "publisher": "", "place": "", "date": "2025-08-22", "volume": "", "issue": "", "section": "Journal of Hydrometeorology", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1175/JHM-D-25-0047.1", "citationKey": "", "url": "https://journals.ametsoc.org/view/journals/hydr/26/8/JHM-D-25-0047.1.xml", "accessDate": "2025-09-29T13:31:11Z", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "journals.ametsoc.org", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-09-29T13:34:01Z", "dateModified": "2025-09-29T13:34:01Z" } }, { "key": "PX5WVPKF", "version": 908, "library": { "type": "group", "id": 538513, "name": "Intercalibration", "links": { "alternate": { "href": "https://www.zotero.org/groups/intercalibration", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/538513/items/PX5WVPKF", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/intercalibration/items/PX5WVPKF", "type": "text/html" } }, "meta": { "createdByUser": { "id": 8722512, "username": "mclachlans", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mclachlans", "type": "text/html" } } }, "creatorSummary": "Liu et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "PX5WVPKF", "version": 908, "itemType": "journalArticle", "title": "Validation of the Calibration Coefficient of the ZY1-02E VNIC Sensor Using Different Calibration Reference", "creators": [ { "creatorType": "author", "firstName": "XN", "lastName": "Liu" }, { "creatorType": "author", "firstName": "QL", "lastName": "Zhou" }, { "creatorType": "author", "firstName": "C", "lastName": "Yang" }, { "creatorType": "author", "firstName": "H", "lastName": "Niu" }, { "creatorType": "author", "firstName": "W", "lastName": "Chen" }, { "creatorType": "author", "firstName": "X", "lastName": "Tang" }, { "creatorType": "author", "firstName": "XY", "lastName": "Liang" }, { "creatorType": "author", "firstName": "XH", "lastName": "Dou" } ], "abstractNote": "ZY1-02E is a medium-resolution hyperspectral operational satellite equipped with a Visible-Near Infrared Camera (VNIC), an Advanced Hyperspectral Imager (AHSI), and a Thermal Infrared Sensor (IRS). These instruments collectively provide detailed geo-morphological data that enhance environmental and resource monitoring applications. Achieving high-precision radiometric calibration is essential to fully leverage the data from ZY1-02E. This study evaluates the on-orbit radiometric performance of the ZY1-02E VNIC sensor through two calibration methods: vicarious radiometric calibration and cross-calibration. For vicarious calibration, synchronized satellite-ground observation experiments were carried out at the Dunhuang radiometric calibration site (DRCS). The reflectance-based approach was employed to validate the absolute radiometric accuracy of the VNIC. For cross-calibration, data from ZY1-02E VNIC obtained during synchronized overpasses of the DRCS were calibrated against reference sensors including Landsat-8 OLI, Landsat-9 OLI2, and Sentinel-2 MSI. Calibration coefficients were derived, and their accuracy was quantitatively evaluated. The results demonstrate that the vicarious radiometric calibration achieves an average accuracy better than 6% in the visible and near-infrared (NIR) bands, with the calibration from April showing superior performance to that of October. The average relative difference among calibration outcomes derived from various reference sensors is maintained within 2.89%, with Landsat-9 OLI2 exhibiting the closest alignment to the vicarious calibration results, showing an average relative difference of only 1.96%. Overall, the ZY1-02E VNIC sensor displays stable and excellent on-orbit radiometric performance, which is pivotal for supporting quantitative applications in environmental monitoring and resource management.", "publicationTitle": "IEEE ACCESS", "publisher": "", "place": "", "date": "2025", "volume": "13", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "147330-147342", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1109/ACCESS.2025.3599676", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "2169-3536", "archive": "", "archiveLocation": "WOS:001560237600017", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2025-09-29T13:34:01Z", "dateModified": "2025-09-29T13:34:01Z" } } ]