陆探一号干涉SAR在轨测试阶段基线精化与DEM精度分析  

Baseline refinement and DEM accuracy analysis during the in-orbit test phase of LT-1 SAR

作　　者：宋鑫友 张磊 李涛 雷宝成 宋瑞庆 SONG Xinyou;ZHANG Lei;LI Tao;LEI Baocheng;SONG Ruiqing(College of Surveying and Geo-Informatics,Tongji University,Shanghai 200092,China;Land Satellite Remote Sensing Application Center,Ministry of Natural Resources of P.R.,Beijing 100048,China)

机构地区：[1]同济大学测绘与地理信息学院,上海200092 [2]自然资源部国土卫星遥感应用中心,北京100048

出　　处：《测绘学报》2024年第10期1920-1929,共10页Acta Geodaetica et Cartographica Sinica

基　　金：国家重点研发计划(2021YFC3000402);国家自然科学基金(42174005)。

摘　　要：陆地探测一号(LT-1)是我国乃至全球首个主要用于地表形变干涉测量应用的L波段雷达遥感双星星座。本文利用LT-1卫星获取的甘肃地区的绕飞SAR数据,分析了差分干涉图中因轨道误差引起的相位斜坡的空间特征,明确了平行基线分量变化率估计误差较大是引起轨道相位斜坡的主导因素。针对现有方法存在的一些局限性,发展了一种基于快速傅里叶变换(FFT)的迭代基线精细化估计方法,并基于校正后的基线开展了研究区数字高程模型(DEM)重建。通过SRTM、AW3D与哥白尼DEM对LT-1 DEM的产品质量进行综合评估与分析,结果表明,本文方法可有效校正残余基线误差,相比于非迭代FFT算法精度提升约16.64%;LT-1 DEM与SRTM、AW3D和哥白尼DEM的平均偏差分别为5.49、3.41及1.94 m,表现出优异的高程精度与现势性优势。Lutan-1(LT-1)is the first L-band radar satellite constellation in China primarily utilized for surface deformation measurements.This study utilized SAR data from the LT-1 satellite over the Gansu region to analyze the spatial characteristics of phase ramps in differential interferograms caused by orbital errors.The findings indicated that significant errors in the estimation of parallel baseline component variation rates were the primary factor contributing to orbital phase ramps.In response to some limitations of existing methods,an iterative baseline refinement estimation method based on Fast Fourier Transform(FFT)is developed.Subsequently,three-dimensional surface reconstruction of the study area is conducted based on the corrected baselines.Finally,the quality of the LT-1 DEM product is comprehensively assessed and analyzed using SRTM,AW3D,and Copernicus digital elevation model.Results indicate that the new method effectively corrects residual baseline errors,with an approximately 16.64%improvement in accuracy compared to non-iterative FFT algorithms.The average deviations of the LT-1 DEM from SRTM,AW3D,and Copernicus DEMs are 5.49 m,3.41 m,and 1.94 m,respectively,demonstrating outstanding elevation accuracy and timeliness advantages.

关 键 词：陆探一号 INSAR 轨道误差 迭代FFT DEM精度分析 

分 类 号：P228.4[天文地球—大地测量学与测量工程]