Reflectance-based calibration of Beijing-1 micro-satellite

To fulfill the objectives of Beijing-1 micro-satellite on-orbit calibration experiment, two in-flight calibration experiments were carried out on September 3 and 13, 2008 at Dunhuang Calibration Site. Two simultaneous datasets including Beijing-1 data and the in-situ surface reflectance and atmospheric measurements, were acquired at the calibration area. During the period of the calibration experiments, some dark sea images were captured to calculate the dark current of Biejing-1. With the reflectance of calibration targets, the atmospheric optical depths, and the water vapor constraints, the 6S radiative transfer code was used to calculate the equivalent radiance of Beijing-1 to the top of the atmosphere (TOA). The reflectance calibration algorithm was taken to calculate the absolute radiometric calibration coefficients of Beijing-1 multi-spectral cameras. The calibration results of Sep. 3 and that of Sep. 13 are very similar. The biggest relative error between the two results is only 3.77%. This proves the calibration results are reasonable.