An Accurate Motion Compensation for SAR Imagery based on INS/GPS with Dual-filter Correction

Abstract

Current Motion Compensation (MOCO) methods using Inertial Navigation System (INS)/Global Positioning System (GPS) integrated systems have provided an important advance in Synthetic Aperture Radar (SAR) imagery, but most of these methods only work well over a short imaging period. With the development of high-resolution SAR that provides image gathering over long periods, the need for higher levels of INS/GPS performance than normally available is desired. The higher requirement of INS/GPS for SAR MOCO is two-fold: (1) the accurate knowledge of location information, and (2) the smoothness of relative change in navigation error. In this paper, we design an INS/GPS architecture with dual-filter correction to obtain accurate absolute velocity and position measurement information with smooth low relative error noise over a long image gathering period. Real SAR data experimental results show that the proposed method effectively improves the MOCO performance of INS/GPS with long SAR imaging periods, in which the SAR azimuth resolution reaches 1·45 m, which is very close to the design value of 1 m.

Multi-Node Motion Estimation Method Based on B-Spline of Array Position and Orientation System

“…The aerial earth observation platform with multiple tasks and functions is the frontier development direction of aerial remote-sensing technology, and the attitude and position precision of the aerial earth observation platform is critical to the precision of multiple measuring instruments such as the aerial cameras, imaging spectrometers, scanning laser and synthetic aperture radar installed on it [1][2][3][4]. Especially, the measuring instruments are installed on different positions of the airplane, so the several inertial measurement units (IMUs) should be equipped with measuring instruments to accurately obtain attitude and position information with transfer alignment at multiple nodes [5][6][7][8].…”