摘要
针对搭载于环境减灾二号A/B(HJ-2A/B)卫星的偏振扫描大气校正仪(PSAC),详细分析了信号链路中各噪声项及其与信号的相关性,建立了信号-总噪声功率线性(S-TNPL)模型,通过实验测量获得了各通道的噪声功率只随信号变化的模型系数,以及与信号无关而与工作条件有关的本底噪声功率(截距);使用在轨实测的本底噪声,建立了不依赖于均质性区域场景的在轨信噪比评估方法,并与星上漫射板法进行了对比验证。结果显示,利用S-TNPL模型与星上漫射板法获得的PSAC在轨信噪比评估结果的相对偏差为-0.62%~6.27%,具有较好的一致性,验证了所提在轨信噪比评估方法的合理性。该信噪比评估方法不仅能适应在轨辐射性能衰退的情况,同时能方便实现不同辐亮度条件下的信噪比转换,并可直接对任意单次观测结果的信噪比进行评估。该信噪比分析方法理论上同样适用于其他光学遥感器,可为其在轨信噪比评估提供参考。
For the polarized scanning atmospheric corrector(PSAC)onboard the Huanjing Jianzai-2A/B(HJ-2A/B)satellites,this study analyzes the noise terms in the signal chain and their correlation with the signal in detail and builds a signal-total noise power linear(S-TNPL)model.Experimental measurements are conducted to obtain the coefficient of the model in which the noise power of each channel only varies with the signal and the background noise power(intercept)that is related to operating conditions rather than to the signal.An on-orbit signal-to-noise ratio(SNR)evaluation method independent of homogeneous regional scenes is developed with background noise measured on orbit and is then verified by a comparison with the onboard diffuser method.The comparison shows that the results of the on-orbit SNR evaluation of the PSAC obtained by the proposed S-TNPL model and the onboard diffuser method exhibit a relative deviation of-0.62%-6.27%,indicating favorable consistency and thus verifying the validity of the proposed on-orbit SNR evaluation method.This SNR evaluation method can not only adapt to degrading on-orbit radiation performance but also facilitate the conversion of SNRs under different radiance conditions.Moreover,it can be directly applied to evaluate the SNR of the result of any single observation.The SNR analysis method in this paper is also applicable to other optical remote sensors theoretically and can thus provide a reference for the on-orbit SNR evaluation of such remote sensors.
作者
董浩
刘振海
赵鑫鑫
雷雪枫
陶菲
楚宇恒
邹鹏
宋茂新
丛强
洪津
Dong Hao;Liu Zhenhai;Zhao Xinxin;Lei Xuefeng;Tao Fei;Chu Yuheng;Zou Peng;Song Maoxin;Cong Qiang;Hong Jin(Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,Anhui,China;University of Science and Technology of China,Hefei 230027,Anhui,China;Key Laboratory of Optical Calibration and Characterization,Chinese Academy of Sciences,Hefei 230031,Anhui,China;DFH Satellite Co.,Ltd.,Beijing 100094,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2022年第24期36-44,共9页
Acta Optica Sinica
基金
王宽诚率先人才计划“卢嘉锡国际合作团队项目”(GJTD-2018-15)
中国科学院合肥研究院院长基金(YZJJ202201-TS)。
关键词
大气光学
环境减灾二号卫星
大气校正仪
噪声模型
信噪比评估
太阳漫射板
atmospheric optics
HJ-2 satellite
atmospheric corrector
noise model
signal-to-noise ratio evaluation
solar diffuser
