TOPS模式哨兵-1雷达干涉图误差校正技术

哨兵-1系统因其优质的设备参数及开放性的政策具有很高的学术及应用价值，然而其特殊的TOPS成像模式对利用该数据的干涉处理与分析提出了挑战。本文对影响哨兵-1 TOPS模式数据干涉质量的数据配准、电离层及对流层因素进行了定量化分析，提出了基于ESD，以及GPS、ECMWF等外部数据源校正的TOPS哨兵-1模式干涉图误差校正技术；以一对2016年某区域的哨兵-1 TOPS模式影像为研究数据，对其依次进行了精配准、电离层相位和对流层相位系统校正。研究结果表明，配准精度能够满足数据1/1000像元的精度要求；能去除电离层条带相位和方位向相位跳变；进而实现对流层相位约27%标准差精度的提升。此技术能够显著减小哨兵-1 TOPS模式数据的干涉误差，提高其在差分雷达干涉乃至时序差分雷达干涉等形变监测中的应用价值。

Error correction of TOPS Sentinel-1 interferograms

Because of the high quality and the open source policy of the Sentinel-1 SAR data, InSAR studies using Sentinel-1 is essential for technology promotion and application. However, the characteristics of TOPS acquiring mode bring in challenges for the interferogram generation of Sentinel-1 data. This paper implements quantitative analyses of three main issues that causing poor quality of Sentinel-1 interferogram of TOPS mode, including image coregistration, ionosphere phase correction and troposphere phase correction. After that, an effective solution based on ESD algorithm, GPS data and ECMWF data is proposed to solve the aforementioned problems. A pair of Sentinel-1 TOPS mode images acquired in 2016 are chosen as the study data. It turns out that the derived interferogram achieves the requirement of 1/1000 coregistration precision, in conjunction with the corrected linear trend and burst phase-jump from ionosphere difference. The phase error due to the troposphere difference reduces approximately 27% in standard deviation after the tropospheric phase correction. The proposed solution significantly enhances the quality of Sentinel-1 TOPS mode interferogram that is feasible in motion estimation using DInSAR and time series DInSAR approaches.