中国空间科学技术

中国空间科学技术 ›› 2024, Vol. 44 ›› Issue (5): 147-154.doi: 10.16708/j.cnki.1000-758X.2024.0082

• 论文 • 上一篇    下一篇

国产C波段SAR卫星绝对辐射定标精度验证

邓明军，陈志远，张过，刘宁，杨银   

  1. 1 湘潭大学 自动化与电子信息学院，湘潭411105
    2 武汉大学 测绘遥感信息工程国家重点实验室，武汉430000
    3 湘潭大学 数学与计算科学学院，湘潭411100
    4 湖南国家应用数学中心，湘潭411100
  • 出版日期:2024-10-25 发布日期:2024-10-21

Absolute radiometric calibration accuracy verification of domestic C-band satellite

DENG Mingjun，CHEN Zhiyuan，ZHANG Guo，LIU Ning，YANG Yin   

  1. 1 School of Automation and Electronic Information，Xiangtan University，Xiangtan 411105，China
    2 State Key Laboratory of Information Engineering in Surveying，Mapping and Remote Sensing，Wuhan University，
    Wuhan 430000，China
    3 School of Mathematics and Computational Science，Xiangtan University，Xiangtan 411100，China
    4 National Centre for Applied Mathematics in Hunan，Xiangtan 411100，China
  • Published:2024-10-25 Online:2024-10-21

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摘要： SAR图像测量地球物理参数，实现定量遥感应用，对辐射定标精度有严格要求，因此需要对SAR卫星进行辐射定标精度验证。通过雷达方程推算出雷达散射截面积、定标常数与图像DN值三者之间的关系，并利用宁夏中卫定标场有源定标器及其SAR图像做定标验证实验。实验结果表明，高分三号02星数据绝对辐射定标精度较高，其中积分法辐射定标精度为0.65dB，而峰值法定标精度为0.57dB；海丝1号卫星数据辐射定标精度为1~2dB，计算定标常数时保持相同波位可有效提高定标常数的稳定性。

关键词: 绝对辐射定标, 绝对定标常数, 积分法, 峰值法, 波位

Abstract: SAR images have strict requirements on the accuracy of radiometric calibration in the measurement of geophysical parameters and the realization of quantitative remote sensing applications.Therefore，the radiometric calibration verification of the SAR satellites is carried out.The relationship between the backscattering coefficient，the calibration constant and the image DN value is calculated with the radar equation，and the calibration verification experiment is carried out by using the active calibrator of Ningxia Zhongwei Calibration Field and its SAR image.The experimental results show that the absolute radiometric calibration accuracy of GF-3 02 satellite data is very high，in which the integration radiometric calibration accuracy is 0.65dB，while the peak calibration accuracy is 0.57dB；the radiometric calibration accuracy of the HISEA-1 satellite data is about 1.2dB.Maintaining the same wave position when calculating the calibration constant can effectively improve the stability of the calibration constant.

Key words: absolute radiometric calibration, absolute calibration constant, integration method, peak value method, wave position