Vector network analyzer (VNA) based synthetic aperture radar (SAR) imaging

Synthetic Aperture Radar (SAR) is an all-weather, day and night imaging tool. It can penetrate ground and foliage. In SAR imaging, a small antenna is mounted on platforms like aircraft, UAV or satellite and range profiles are collected along flight path and after applying SAR reconstruction algorithm to the recorded data, SAR image is obtained. In this work an X-band Step Frequency Continuous Wave (SFCW) based SAR imaging system has been developed using Rhode & Schwarz ZVB20 Vector Network Analyzer (VNA) and antenna linear positioning system. The motor drive of antenna linear positioning system moves transmit and receive antennas to a cross-range position, stops and the antennas acquire range profile in frequency domain. This process is repeated at regular intervals along the guide-rail until the antennas reach the end of the rail. The recorded data is in the form of 2D data matrix. After the application of Range Migration Algorithm (RMA) to the recorded phase history data of range profiles, SAR image is reconstructed.