{"title":"Automatic Extraction of 3-D Ground Control Points Using Stereo SAR from China’s GF3B and SVN2-01/02","authors":"Minzheng Mu;Zhiwei Li;Xin He;Qijin Han;Xiaoyu Shi;Ya Zhang;Yunce Su;Pengfei Li;Yan Zhu","doi":"10.1109/JSTARS.2025.3602096","DOIUrl":null,"url":null,"abstract":"The extraction of ground control points (GCPs) from spaceborne synthetic aperture radar (SAR) is an effective technique for rapid, contactless, and globally available georeferencing. In recent years, China has made significant progress in the deployment and application of SAR satellites. However, the automatic derivation of high-precision GCPs remains challenging, primarily due to two key factors: 1) the need for high-accuracy calibration of SAR geometric observations and 2) the automatic detection and matching of candidate GCPs (CGCPs) across SAR images acquired from different look angles. This article proposed an improved algorithm framework for GCP extraction and demonstrated the application potential of China’s SAR satellites. The main improvements are as follows. 1) Beam-dependent biases are incorporated into the geometric calibration process to achieve higher ranging accuracy. 2) A CGCP detector is designed that leverages shape characteristics to robustly identify CGCPs without relying on any external data. 3) An integrated matching scheme is proposed, which combines preprocessing, feature description, and transformation-search strategies to enable effective pairing of CGCPs. SAR imagery from China’s Gaofen-3B and Superview Neo-2 01/02 satellites is utilized, and geometric calibration is performed using the open-access corner reflector array in Australia. GCP extraction experiments are conducted in the Suzhou area, with 7477 GCPs automatically extracted and a root mean square error better than 1 m.","PeriodicalId":13116,"journal":{"name":"IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing","volume":"18 ","pages":"22029-22046"},"PeriodicalIF":5.3000,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11134818","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/11134818/","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
The extraction of ground control points (GCPs) from spaceborne synthetic aperture radar (SAR) is an effective technique for rapid, contactless, and globally available georeferencing. In recent years, China has made significant progress in the deployment and application of SAR satellites. However, the automatic derivation of high-precision GCPs remains challenging, primarily due to two key factors: 1) the need for high-accuracy calibration of SAR geometric observations and 2) the automatic detection and matching of candidate GCPs (CGCPs) across SAR images acquired from different look angles. This article proposed an improved algorithm framework for GCP extraction and demonstrated the application potential of China’s SAR satellites. The main improvements are as follows. 1) Beam-dependent biases are incorporated into the geometric calibration process to achieve higher ranging accuracy. 2) A CGCP detector is designed that leverages shape characteristics to robustly identify CGCPs without relying on any external data. 3) An integrated matching scheme is proposed, which combines preprocessing, feature description, and transformation-search strategies to enable effective pairing of CGCPs. SAR imagery from China’s Gaofen-3B and Superview Neo-2 01/02 satellites is utilized, and geometric calibration is performed using the open-access corner reflector array in Australia. GCP extraction experiments are conducted in the Suzhou area, with 7477 GCPs automatically extracted and a root mean square error better than 1 m.
期刊介绍:
The IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing addresses the growing field of applications in Earth observations and remote sensing, and also provides a venue for the rapidly expanding special issues that are being sponsored by the IEEE Geosciences and Remote Sensing Society. The journal draws upon the experience of the highly successful “IEEE Transactions on Geoscience and Remote Sensing” and provide a complementary medium for the wide range of topics in applied earth observations. The ‘Applications’ areas encompasses the societal benefit areas of the Global Earth Observations Systems of Systems (GEOSS) program. Through deliberations over two years, ministers from 50 countries agreed to identify nine areas where Earth observation could positively impact the quality of life and health of their respective countries. Some of these are areas not traditionally addressed in the IEEE context. These include biodiversity, health and climate. Yet it is the skill sets of IEEE members, in areas such as observations, communications, computers, signal processing, standards and ocean engineering, that form the technical underpinnings of GEOSS. Thus, the Journal attracts a broad range of interests that serves both present members in new ways and expands the IEEE visibility into new areas.