敦煌国家辐射校正场每年都开展大量实验，为国内外对地观测卫星提供定标服务，但多年来敦煌场进行像元尺度地表反射率获取工作时，有关地面光谱采样方案准确度的研究较少。为定量评估不同地面采样方法的准确度，确定不同像元尺度地表反射率获取时采样点的最佳位置，实现敦煌场高精度高效率业务化测量，利用敦煌高分辨率无人机数据与GF-1卫星2 m全色数据对不同像元尺度地表反射率采样方法准确度进行定量分析。研究结果表明：获取陆地卫星像元尺度地表反射率，建议在敦煌150 m国家场的位置用5点系统采样方案初步标定2 m样方位置，并用光谱仪在各2 m样方内用5点系统采样法进行测量；对于气象卫星像元尺度，建议在新选3 km场地用5点模拟退火采样方案确定2 m样方位置，并用光谱仪在各2 m样方内用5点系统采样法进行测量。

A large number of experiments are conducted at Dunhuang national radiometric correction field every year to provide calibration services for earth-observation satellites at home and abroad. However, over several years, there are only few studies regarding the accuracy of the ground spectral sampling scheme when Dunhuang field obtains pixel-scale surface reflectance. To quantitatively evaluate the accuracy of different ground sampling schemes, the best sampling point locations were determined to obtain the surface reflectance at different pixel scales and realize high-precision and high-efficiency operational measurement of Dunhuang field. The accuracy of surface reflectance sampling methods at different pixel scales was analyzed quantitatively using Dunhuang’s high-resolution unmanned aerial vehicle data and 2 m panchromatic data from the GF-1 satellite. Based on the results, a five-point system sampling scheme is suggested to obtain pixel-scale surface reflectance from Landsat by preliminarily calibrating a 2 m quadrat within the 150 m national field in Dunhuang. For the pixel-scale resolution of meteorological satellites, the five-point-simulated annealing sampling scheme is suggested to determine the position of the 2 m quadrat in the newly selected 3 km site. In both the cases, a spectrometer is used to measure the five-point system sampling method in each 2 m quadrat.