Systems Engineering and Electronics ›› 2026, Vol. 48 ›› Issue (3): 846-858.doi: 10.12305/j.issn.1001-506X.2026.03.12

• Sensors and Signal Processing • Previous Articles    

A geometric positioning technology based on antenna pointing for large azimuth scanning sliding-spot mode of spaceborne SAR

Yingying LI, Hao WU, Feng CHEN, Yuzhuoyue LIN, Xueying WANG, Xin FENG   

  1. Beijing Institute of Remote Sensing Information,Beijing 100011,China
  • Received:2024-12-30 Online:2026-03-25 Published:2026-04-13
  • Contact: Yingying LI

Abstract:

Because of the dechirp operation in the imaging algorithm of the sliding-spot mode, it is difficult to construct a rigorous range-Doppler equation for its geometric processing. In regard to this, a conformation model based on synthetic aperture radar (SAR) antenna pointing vector is presented, which fully considering the influence of the dechirp operation on the sliding-spot imaging. Starting from the relative position between the image points of each scanning line in SAR images and the satellite, based on accurate satellite-to-ground geometric conditions, a strict transformation model between image point coordinates and geographic coordinates is established. Based on this model, the forward and inverse solution processes for SAR geometric positioning in sliding mode are given. Finally, geometric calibration and positioning processing experiments using different pulse width combinations and different field data showed that after compensating for various geometric errors caused by the SAR payload itself, atmospheric transmission, platform orbit position, elevation, and other factors, the uncontrolled geometric positioning accuracy of the sliding-spot image can reach 1?2 m, fully demonstrating the effectiveness of the proposed method in the geometric positioning of sliding-spot images.

Key words: synthetic aperture radar (SAR), sliding-spot imaging, dechirp, range-Doppler (RD), geometric positioning

CLC Number: 

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