测绘学报 ›› 2025, Vol. 54 ›› Issue (2): 321-333.doi: 10.11947/j.AGCS.2025.20240132

• 摄影测量学与遥感 • 上一篇    

卫星激光测高产品定位精度初步验证与分析

于启凡1,2,3(), 付安民2, 李少宁1(), 刘晓彤2   

  1. 1.湖南科技大学地理空间信息技术国家地方联合工程实验室,湖南 湘潭 411201
    2.国家林业和草原局林草调查规划院,北京 100714
    3.海南国际商业航天发射有限公司,海南 文昌 571300
  • 收稿日期:2024-04-07 发布日期:2025-03-11
  • 通讯作者: 李少宁 E-mail:yqf@mail.hnust.edu.cn;lsn@hnust.edu.cn
  • 作者简介:于启凡(1998—),男,硕士,研究方向为星载激光雷达数据处理。 E-mail:yqf@mail.hnust.edu.cn
  • 基金资助:
    国家重点研发计划(SQ2022YFB3900026);湖南省自然科学基金(2023JJ30233);智慧地球重点实验室开放基金(KF2023YB02-03);湖南省教育厅资助科研项目(24B0451)

Preliminary verification and analysis of positioning accuracy of the satellite laser altimetry products

Qifan YU1,2,3(), Anmin FU2, Shaoning LI1(), Xiaotong LIU2   

  1. 1.National-Local Joint Engineering Laboratory of Geo-Spatial Information Technology, Hunan University of Science and Technology, Xiangtan 411201, China
    2.Academy of Inventory and Planning, National Forestry and Grassland Administration, Beijing 100714, China
    3.Hainan International Commercial Aerospace Launch Co., Ltd., Wenchang 571300, China
  • Received:2024-04-07 Published:2025-03-11
  • Contact: Shaoning LI E-mail:yqf@mail.hnust.edu.cn;lsn@hnust.edu.cn
  • About author:YU Qifan (1998—), male, master, majors in spaceborne LiDAR data processing. E-mail: yqf@mail.hnust.edu.cn
  • Supported by:
    The National Key Research and Development Program of China(SQ2022YFB3900026);The Natural Science Foundation of Hunan Province, China(2023JJ30233);The Key Laboratory of Smart Earth, China(KF2023YB02-03);The Project supported by the Scientific Research Fund of Hunan Provincial Education Department(24B0451)

摘要:

有效评价卫星激光测高数据的几何定位精度是保障其产品应用的基础和前提。卫星在轨后激光光轴指向和平台稳定会随时间推移发生变化,从而引起激光光斑在地面定位位置出现偏差。本文针对句芒号卫星激光测高系统的工作模式,首先对激光足印相机上的光斑位置和光轴指向进行确定,提出一种基于光斑能量梯度最大的椭圆拟合方法(MG-EFM),分析卫星在轨后激光出射指向的稳定性;再利用高精度地形数据标校激光足印点在地面的位置,对激光几何定位精度进行分析。试验结果表明:①MG-EFM方法提取足印光斑中心的精度优于0.1像素,可用于激光光轴指向的稳定性监测,并对短期内激光光轴的漂移误差进行有效识别;②在东北虎豹国家公园地区句芒号激光几何定位相对稳定,发现随着卫星测量环境和观测时间的不同,激光光斑定位呈现时变性的误差分布特性,尤其是昼夜观测的激光光斑在地面定位存在10 m左右的不一致性。为满足卫星激光测高产品的业务化应用需求,后续应增加地面控制数据来提升产品的几何稳定性。

关键词: 激光测高, 足印相机, 定位精度分析, 稳定性监测, 句芒号, 陆地生态系统碳监测卫星

Abstract:

Effective evaluation of the geometric positioning accuracy of satellite laser altimetry products is the basis and prerequisite for safeguarding their subsequent applications. After the satellite is in orbit, the laser optical axis pointing and platform stability will change over time, leading to deviations in the positioning position of the laser spot on the ground. Aiming at the working mode of the laser altimetry system of the Gou Mang satellite, this paper first determines the spot position on the laser footprint camera and the optical axis pointing, and proposes an ellipse fitting method based on the maximum gradient of spot energy (MG-EFM) to analyze the stability of the laser emission pointing after the satellite is in orbit. Then, the position of the laser footprint point on the ground is calibrated using high-precision terrain data to analyze the geometric positioning accuracy of the laser. The experimental results show that: ①The MG-EFM method extracts the center of the laser spot with an accuracy of better than 0.1 pixel, which can be used for monitoring the stability of the laser optical axis pointing and effectively identifying the drift error of the laser optical axis in the short term. ②The laser geometric positioning of the Gou Mang in the Northeast Tiger and Leopard National Park area is relatively stable. However, it has been found that with variations in the satellite measurement environment and observation time, the laser spot positioning exhibits time-varying error distribution characteristics, especially there is an inconsistency of about 10 m in the ground positioning of the laser spots observed during day and night. To meet the operational application requirements of satellite laser altimetry products, ground control data should be added to enhance the geometric stability of the products.

Key words: laser altimetry, footprint camera, positioning accuracy analysis, stability monitoring, Gou Mang, terrestrial ecosystem carbon inventory satellite

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