## 6 Conclusions  
This study proposed a pixel-by-pixel synchronous atmospheric correction method for wide-swath, wide-field imaging, specifically designed for the HJ-2A/B MSC, while incorporating BRDF effects. The method integrates real-time atmospheric parameter retrieval using the PSAC, a radiative transfer model-based correction approach, and a semi-empirical BRDF correction.  
Validation experiments demonstrated significant improvements in image contrast, clarity, and surface reflectance accuracy. Compared to pre-atmospheric correction images, the corrected images exhibited at least a 35.63% increase in contrast and a minimum 90.51% improvement in clarity. Comparisons with in situ measurements showed maximum deviations below 0.03, while validation against Sentinel-2 surface reflectance products confirmed that most deviations were below 0.04, highlighting the reliability of the correction method.  
By leveraging synchronous atmospheric parameters, this method significantly improves the quality of wide-field remote sensing images and generates high-precision reflectance products. These products provide reliable data support for applications such as disaster monitoring, water resource management, and crop monitoring. Future work will focus on refining BRDF correction for mountainous regions to enhance the accuracy of surface reflectance retrieval in these complex terrains.  
This work was carried out in collaboration with all of the authors. Conceptualization, H.H., X.L. ([PERSON]) and X.S.; methodology, H.H.; software, Y.W.; validation, H.H., X.L. ([PERSON]) and R.T.; data acquisition, H.H., Z.L., X.L. ([PERSON]), J.L. and L.F.; writing and revision, H.H. All authors have read and agreed to the published version of the manuscript.  
This work was supported, in part, by the Aerospace Science and Technology Innovation and Application Research Project under Grant E23Y0H555S1 and Grant 6250251020 and, in part, by the Key Laboratory Fund Programme of the Chinese Academy of Sciences under Grant E33Y0 HB42P1.  
The HJ-2A/B satellite images and PSAC data can be obtained from the China Centre for Resources Satellite Data and Application (available online: [[https://data.cresda.cn/#/home](https://data.cresda.cn/#/home)]([https://data.cresda.cn/#/home](https://data.cresda.cn/#/home)) (accessed on 13 January 2025)). MODIS data can be downloaded from the official website of NASA ([[https://ladsweb.modaps.eosdis.nasa.gov/](https://ladsweb.modaps.eosdis.nasa.gov/)]([https://ladsweb.modaps.eosdis.nasa.gov/](https://ladsweb.modaps.eosdis.nasa.gov/)), last accessed on 17 January 2025). Sentinel-2 data can be downloaded from the official website of ESA ([[https://dataspace.copernicus.eu/](https://dataspace.copernicus.eu/)]([https://dataspace.copernicus.eu/](https://dataspace.copernicus.eu/)), last accessed on 23 January 2025).  
**Acknowledgments:** The MODIS data used in this study were provided by the National Aeronautics and Space Administration (NASA), and the Sentinel-2 data were provided by the European Space Agency (ESA). The authors sincerely thank their support in providing the data for this research.  
**Conflicts of Interest:** The authors declare no conflicts of interest.