测绘学报 ›› 2025, Vol. 54 ›› Issue (6): 1009-1020.doi: 10.11947/j.AGCS.2025.20240426

• 大地测量学与导航 • 上一篇    下一篇

顾及森林区穿透深度影响的LT-1 InSAR区域网平差

吴可夫1(), 付海强1(), 朱建军1, 韩启金2, 王爱春2, 张明霞2, 李志伟1   

  1. 1.中南大学地球科学与信息物理学院,湖南 长沙 410083
    2.中国资源卫星应用中心,北京 100094
  • 收稿日期:2024-10-16 修回日期:2025-05-14 出版日期:2025-07-14 发布日期:2025-07-14
  • 通讯作者: 付海强 E-mail:kefuwu@csu.edu.cn;haiqiangfu@csu.edu.cn
  • 作者简介:吴可夫(2000—),男,博士生,研究方向为InSAR地形测绘及区域网平差。E-mail:kefuwu@csu.edu.cn
  • 基金资助:
    国家自然科学基金(42227801);国家杰出青年科学基金(41925016);湖南省自然科学基金优秀青年基金(2023JJ20061)

LT-1 InSAR block adjustment considering the impact of penetration depth in forest areas

Kefu WU1(), Haiqiang FU1(), Jianjun ZHU1, Qijin HAN2, Aichun WANG2, Mingxia ZHANG2, Zhiwei LI1   

  1. 1.School of Geosciences and Info-Physics, Central South University, Changsha 410083, China
    2.China Centre for Resources Satellite Data and Application, Beijing 100094, China
  • Received:2024-10-16 Revised:2025-05-14 Online:2025-07-14 Published:2025-07-14
  • Contact: Haiqiang FU E-mail:kefuwu@csu.edu.cn;haiqiangfu@csu.edu.cn
  • About author:WU Kefu (2000—), male, PhD candidate, majors in InSAR topographic mapping and regional network adjustment. E-mail: kefuwu@csu.edu.cn
  • Supported by:
    The National Natural Science Foundation of China(42227801);The National Science Foundation for Distinguished Young Scholars of China(41925016);The Natural Science Foundation of Hunan Province(2023JJ20061)

摘要:

首个L波段干涉SAR星座陆探1号(LT-1)因其强穿透力在林下地形测绘领域具有独特优势。联合高程控制点(星载LiDAR)和连接点进行区域网平差以校准系统误差,是LT-1开展大范围林下地形制图的基础。然而,为规避森林散射引发InSAR测高偏离LiDAR这一问题,现有区域网平差方法仅选取裸地点,易引发系统误差的病态观测。鉴于此,本文利用刻画森林散射过程的SINC模型补偿InSAR测高偏差,建立顾及穿透深度影响的区域网平差模型。为验证本文方法的有效性,选取森林覆盖度为85%和50%的两个试验区进行了测试。结果表明,本文估计的LT-1 DEM相对传统方法提升了22.1%和12.5%的测高精度,高程精度和林区穿透率与COP-DEM、SRTM、AW3D相比均处于最高水平。同时,基于SINC模型估计的LT-1林下地形相对LT-1 DEM提升了40.6%和25.5%的测高精度,RMSE分别为3.15 m和2.80 m。

关键词: 区域网平差, 合成孔径雷达干涉测量, 陆探1号, 数字高程模型, 林下地形, SINC模型

Abstract:

Due to its intense penetration, the first L-band interferometric SAR constellation, LuTan-1 (LT-1), has unique advantages in sub-canopy topography mapping. The block adjustment utilizes height control points (spaceborne LiDAR) and tie-points to calibrate the systematic error, which is the basis for LT-1 to carry out large-scale sub-canopy topography mapping. However, to avoid the problem of InSAR altimetry deviation from LiDAR caused by forest scattering, the existing block adjustment methods only select bare-earth points, which are prone to pathological observations with systematic error. Given this, this paper uses the SINC model that describes the forest scattering process to compensate for the InSAR altimetry deviation and establishes a block adjustment model considering the influence of penetration depth. We used two test sites with forest coverage of about 85% and 50% to verify the algorithm's effectiveness. The results show that the LT-1 DEM estimated in this paper improves the height accuracy by 22.1% and 12.5% compared with the traditional method, and the height accuracy and forest penetration rate are at the highest level compared with COP-DEM, SRTM, and AW3D. Furthermore, the LT-1 sub-canopy topography estimated based on the SINC model improved the height measurement accuracy by 40.6% and 25.5% compared with the LT-1 DEM, with RMSE of 3.15 m and 2.80 m, respectively.

Key words: block adjustment, InSAR, LT-1, DEM, sub-canopy topography, SINC model

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