摘要
Abstract
The radiometric performance evaluation of synthetic aperture radar(SAR)data for two 5m S-band SAR(S-SAR)satellites is conducted in this paper.Firstly,noise equivalent sigma ze-ro is evaluated based on echo and internal calibration data.Secondly,relative radiometric accura-cy and radiometric resolution are evaluated based on distributed targets in the SAR data.Finally,based on point target SAR data,side lobe ratio and spatial resolution are evaluated,and a method of cross-radiometric validation for two satellites using point targets is proposed.The validation results show that the SAR data radiometric performance of the 5m S-SAR satellites is better than the design indexes.In strip mode,the noise equivalent sigma zero is better than-20dB(at the beam center),the relative radiometric accuracy is better than 1.5dB within a single scene,the ra-diometric resolution is no more than 4.3dB(for the main polarization,at the beam center),the peak side lobe ratio is better than-20dB,the integrated side lobe ratio is better than-13dB,and the spatial resolution is better than 5m.The relative radiometric accuracy,radiometric resolu-tion,side lobe ratio,and spatial resolution of 01 satellite and 02 satellite are essentially equivalent.However,the noise equivalent sigma zero of 02 satellite is better than that of 01 satellite.The radiomet-ric accuracy difference between the two satellites is between 0.29dB and 1.33dB,which meets the re-quirement that the absolute radiometric accuracy of the 5m S-SAR satellites is better than 2dB,indica-ting the effectiveness of the method of cross radiometric validation based on point targets.关键词
5米S频段合成孔径雷达卫星/合成孔径雷达数据/辐射性能/噪声等效后向散射系数/交叉辐射验证Key words
5m S-SAR satellite/SAR data/radiometric performance/noise equivalent sigma zero/cross radiometric validation分类
天文与地球科学
