摘要
宏图一号(Hongtu-1,HT-1)卫星系统是全球首个采用四星车轮式编队构型的多星分布式干涉雷达卫星系统。与传统合成孔径雷达(synthetic aperture radar,SAR)干涉测量(interferometric SAR,InSAR)系统不同,HT-1具备卫星单航过多基线干涉测量能力,能够同时得到多组不同基线长度的高相干性SAR像对。针对HT-1数据特点,提出一种利用多基线相位解缠的高精度InSAR高程反演方法。首先建立等效相位中心简化辅星成像模型,利用单基SAR几何生成不同基线像对干涉图;然后对去平干涉图进行多基线解缠,恢复绝对地形相位;最后将相位转换为目标场景高程。选取中国河南某地区作为研究区域,对该地区真实地形进行仿真实验,结果表明,干涉车轮多基线系统具有复杂陡峭场景的高程反演能力,非叠掩区域高程均方根误差小于2 m;通过与高分7号和ICESat-2数据获取的实验区地表高程进行对比分析,验证了该方法的有效性和可靠性。
Objectives:The Hongtu-1(HT-1)synthetic aperture radar(SAR)satellite system,the world's first multi-satellite distributed interferometric radar system,utilizes a four-satellite wheel formation to enable single-pass,multi-baseline interferometry.This system provides distinct advantages over traditional inter-ferometric SAR(InSAR)systems by enabling the simultaneous acquisition of high-coherence SAR image pairs with varying baseline lengths.Most existing related research is based on simplified simulation data,overlooking practical challenges in real data processing.Methods:A method for high-precision InSAR ele-vation inversion based on multi-baseline phase unwrapping is proposed,tailored to HT-1's unique data characteristics.The approach involves constructing an equivalent phase center model for auxiliary satel-lites,generating interferograms from single-pass SAR geometry,and performing multi-baseline unwrap-ping on the flattened interferograms to recover the absolute terrain phase.The final phase data is converted into elevation measurements for the target area.Results:Simulation experiments using real terrain data from Henan Province,China,validate the method's effectiveness for elevation inversion in complex and steep terrains.The root mean square error(RMSE)in non-overlapping regions is under 2 meters.A 5 m resolution digital elevation model(DEM)of the experimental area was obtained by inverting the actual single-track HT-1 SAR data.In the overlapping area,the elevation RMSE between HT-1 DEM and GF-7 DEM is under 14 m.Addi ionally,the elevation profile of HT-1 DEM closely aligns with the trend observed in ICESat-2 laser altimetry data.Conclusions:The HT-1 system's wheel constellation and multibaseline interferometry capabilities exhibit substantial potential for high-accuracy topographic mapping.
作者
朱泽尧
赵双明
张文
孟令奎
罗志
李林宜
路聚锋
ZHU Zeyao;ZHAO Shuangming;ZHANG Wen;MENGLingkui;LUO Zhi;LI Linyi;LU Jufeng(School of Remote Sensing and Information Engineering,Wuhan University,Wuhan 430079,China;Piesat Information Technology Co.Ltd,Beijing 100195,China)
出处
《武汉大学学报(信息科学版)》
北大核心
2025年第8期1619-1630,共12页
Geomatics and Information Science of Wuhan University
基金
国家重点研发计划(2021YFB3900603)。
作者简介
第一作者:朱泽尧,博士生,研究方向为InSAR数据处理及形变监测。rszyzhu@whu.edu.cn;通信作者:赵双明,教授。ismzhao@whu.edu.cn。
