Abstract: [Purposes]Since its launch in 2013,GF-1 has been widely applied in fields such as agriculture,forestry,urban environment,and land use change monitoring.As fundamental quantitative product,surface reflectance has long been a focus of attention.To further strengthen the application and promotion of the GF-1 products,this paper carries out extensive verification of the accuracy of the products in overseas regions.[Methods]Using the ACFrC software based on atmospheric lookup tables to perform atmospheric correction on images from GF-1 PMS and WFV sensors in Southeast Asian countries including Thailand,Bangladesh,and Laos.Indicators such as accuracy (A),precision (P) and uncertainty (U) are adopted to evaluate the cross-validation accuracy between GF-1 surface reflectance products and Landsat 8/9 OLI data.[Findings]The results show that for the three regionsthe minimum value of the A,P and U indicators is 6.79×10^-5,and the maximum is 7.82×10^-2,both of which are lower than the error constraint expectation of 0.015+0.15R (R is the surface reflectance),which are 1.90×10^-2 and 8.10×10^-2 respectively.Thus,the products meet the accuracy requirements.So there is a high degree of consistency between the surface reflectance products generated by the ACFrC and Landsat 8/9 data,and the accuracy (A) of cross-validation between the blue band of GF-1 PMS and Landsat 8/9 surface reflectance in Bangladesh and Laos is close to 0,indicating a high level of consistency between the two.[Conclusions]The GF-1 PMS and WFV surface reflectance products generated by the ACFrC system provide preliminary validation for the operational application of such data and offer references for the quantitative application research of global medium-to-high resolution satellite data.

Key words: ACFrC, surface reflectance, cross-validation, GF-1, Landsat 8/9