VSAR Mode And Signal Processing Methods In Battlefield Reconnaissance Radar

As an important sensor, Synthetic Aperture Radar (SAR) is widely used for manymilitary reconnaissance and remote sensing applications. As is known well, SARsystems are designed to image stationary scenes. Moving targets will be displaced inthe SAR image along the azimuth direction, which makes the locations of the targetsdistorted. This is caused by the fact that the radial velocities of the targets can give riseto the Doppler shifts. This location error cannot be avoided in conventional SARsystems, but its influence can be eliminated by adopting some technology.The velocity SAR (VSAR) is a multi-channel radar imaging system capable ofreconstructing the three-dimensional range/azimuth/velocity image for scene thatcontains moving objects. It combines the high resolution imaging capability of SARwith the moving target detection capability of MTI systems. The excellent capability ofmoving target detection allows for a large application potential in reconnaissancemissions.Based on the knowledge of SAR, in this paper we give a detail description of theconcept of VSAR system and the fundamental signal processing algorithms. And wealso analyze the detection performance of the system. Firstly, via the example of stripairborne SAR, the basic principle of SAR imaging is introduced. Then the fact that theVSAR system has good detection ability to low-RCS and slowly moving targets isdiscussed in theory, and simulations also give a demonstration of the fact. Finally inorder to extend the range of the velocity detection, the dual-speed VSAR (DS-VSAR)is introduced. DS-VSAR is generalized by flying with single speed to flying withdual-speed to resolve the azimuth location ambiguity, which is developed from VSAR.Using DS-VSAR, the detection and locations of both slowly and fast moving targetscan be estimated accurately, and meanwhile the clutter can be suppressed.