Design of Inter-satellite Measurement System for Distributed SAR Application

Abstract

Compared with the traditional single-star SAR(synthetic aperture radar) system, the dual-star SAR system has unique advantages in terms of interferometry, tomography, and high-resolution wide-format imaging due to its flexible configuration. When imaging using a dual-star SAR system, it is necessary to accurately obtain the relative position and time information of the two stars. Aiming at the problems of inter-satellite two-way ranging and time synchronization, the method of two-way time comparison is carried out by using the forwarding time of the satellite. Through the extraction of the baseband information, the analysis, calculation and framing of the test frame, the reception of ranging frame and the management of transmission, the proposed system can finish bidirectional ranging. Through innovative framing trigger design and pseudo-range selection design algorithm, the intersatellite measurement system is more suitable for the measurement environment of dual-satellite SAR. Corresponding testing and simulation results show that the proposed technique can substantially improve the accuracy of distributed SAR observation, which is more suitable for the inter-satellite measurement compared to the traditional satellite-to-ground measurement.