Accurate inversion of remote sensing indices images with high-resolution is an important basis for extracting the surface information on fine scale and the remote sensing application with high precision. Under the background that the effect of atmospheric correction on the inversion accuracy of medium-resolution remote sensing indices has been widely concerned, the atmospheric correction method based on the synchronous atmospheric parameters retrieved from the Synchronization Monitoring Atmospheric Corrector (SMAC), which is on board the High Resolution Multi-Mode Integrated Imaging satellite (Gao Fen Duo Mo, GFDM) platform, is proposed. The “Spaceborne - Airborne” synchronous imaging experiment was conducted to investigate the effect of synchronous atmospheric correction on the accuracy of high-resolution remote sensing indices images. The low-altitude synchronous remote sensing indices images were taken as the reference standard, the correlation between the NDVI and NDWI images after synchronous atmospheric correction and the reference images are improved by 4.27% and 12.22%, respectively. The mean errors in average NDVI and NDWI value of sampling plot decreased by 0.2489 and 0.1032, respectively. The average errors in the peak value of change rate of pixel index value are reduced by 0.1194 and 0.2288 in the case of NDVI and NDWI, respectively. Compared with the results of FLAASH, the synchronous atmospheric correction method shows better performance, especially in the targets with low reflectance (the atmospheric radiation contribution is higher than the surface radiation contribution), and in the adjacent area between two different ground objects. The results demonstrate that synchronous atmospheric correction can effectively improve the inversion accuracy of high-resolution remote sensing indices images and its ability of quantitative application.

Atmospheric conditions vary significantly in terms of the temporal and spatial scales. Therefore, it is critical to obtain atmospheric parameters synchronized with an image for atmospheric correction based on radiative transfer calculation methods. On 3 July 2020, the high resolution and multimode imaging satellite, Gao Fen Duo Mo (GFDM), which was the first civilian high-resolution remote sensing satellite equipped with the Synchronization Monitoring Atmospheric Corrector (SMAC), was launched. The SMAC is a multispectral and polarization detection device that is used to retrieve atmospheric parameters that are time-synchronized with the image sensor of GFDM in the same field-of-view. On the basis of the atmospheric parameters obtained from the SMAC, a synchronization atmospheric correction (Syn-AC) method is proposed to remove the influence of the atmosphere and the adjacency effects to retrieve the surface reflectance. The Syn-AC method was applied in the experiments of synchronous atmospheric correction for GFDM images, where the surface reflectance retrieved via the Syn-AC method was compared with the field-measured values. In addition, the classical correction method, the FLAASH, was applied in the experiments to compare its performance with that of the Syn-AC method. The results indicated that the image possessed better clarity and contrast with the blurring effect removed, and the multispectral reflectance was in agreement with the field-measured spectral reflectance. The deviations between the reflectance retrievals of Syn-AC and the field-measured values of the selected targets were within 0.0625, representing a higher precision than that of the FLAASH method (the max deviation was 0.2063). For the three sites, the mean relative error of Syn-AC was 19.3%, and the mean relative error of FLAASH was 76.6%. Atmospheric correction based on synchronous atmospheric parameters can improve the quantitative accuracy of remote sensing images, and it is meaningful for remote sensing applications.