PROJECT TITLE :

Azimuth ambiguity suppression with an improved reconstruction method based on antenna pattern for multichannel synthetic aperture radar systems

ABSTRACT:

For artificial aperture radar (SAR) systems, antenna array which is distributed in flight direction could increase the equivalent sample frequency in azimuth by a factor of the quantity of parts of antenna array. With a reconstruction algorithm, the aliased Doppler spectrum could be recovered. However, the degradation of standard algorithms for reconstructing the Doppler spectrum with special pulse repetition frequency (PRF) shows poor robustness and the out-of-band energy which is caused by the facet lobes of the antenna pattern deteriorates the azimuth ambiguity to signal ratio of a multichannel SAR. During this study, an improved reconstruction algorithm based mostly on antenna pattern is proposed by generating an ambiguity matrix, which resembles the covariance matrix and might be used to reconstruct in-band signal and minimise the azimuth ambiguity energy. Aiming at increasing the robustness of the algorithm, the tactic of diagonal loading is introduced to the approach. Even within the scenario of special PRF, that is shut to the singular purpose, the signal might be successfully reconstructed with the improved approach. Simulation results validate the proposed technique.