星载微光遥感器外场辐射定标光源的研制和检测

Design and test of in-site radiometric calibration reference light source for spaceborne low light level remote sensors

LED外场辐射定标积分球光源基于辐射通量等效理论,用于星载微光遥感器的在轨辐射定标。该定标光源采用12组峰值波长670 nm的LED密集阵列发光单元,每组最大电功率300 W,辐亮度输出达到5.2×10−2 W·cm−2·sr−1,通过等效辐射通量面积校正后,能够适用于10−9 W·cm−2·sr−1量级的微光通道在轨定标。光源的参数检测结果表明:定标光源角度均匀性在±30°以内优于99.6%,平面均匀性优于99.7%,1 h内稳定性优于99.9%,具有优良的辐射特性。在敦煌中国遥感卫星辐射校正场对VIIRS微光通道进行了在轨实测试验,在轨响应结果为8.27×10−9 W·cm−2·sr−1(含月光贡献和大气影响),证明了该外场微光定标光源辐射量值设计的合理性。

Aiming at on-orbit radiation calibration of spaceborne low-light-level remote sensor,an out-site radiation(LED)light source based on the theory of radiation flux equivalence is designed.The designed calibration light source uses twelve 670 nm pick-wavelength LED modules,with each LED module max power dissipation of 300 W,and the max output radiance over 5.2×10−2 W·cm−2·sr−1.Based on the calibrating area of equivalent radiation flux,it can be applied to the on-orbit calibration of low-light-level channels in the order of 10−9 W·cm−2·sr−1.The test results show that the planar uniformity of the source is better than 99.7%at the exit port,the angular uniformity is better than 99.6%within±30°to the exit normal,and the stability of source is better than 99.9%within 1 h.In-orbit test of the low-light-level channel of VIIRS was carried out at the radiation correction field of Dunhuang Chinese remote sensing satellite,on-orbit response results was 8.27×10−9 W·cm−2·sr−1.(including moonlight contribution and atmospheric impact).The rationality of the design of the radiation value of the out-site low-light-level calibration light source proposed in this paper is proved.