Study On The High Squint SAR Parallel Real-time Processing Technology Based On Multi-core DSPs

Synthetic Aperture Radar(SAR) has the characteristics of all-weather, all-time, long distance as well as two-dimensional imaging, which can greatly improve the radar’s capability to obtain information. High squint SAR can obtain the two-dimensional high resolution image information of the target area in side-front of the platform, which can increase the capability of signal-to-clutte ratio and target recognition capability in the complex background. As a result, it has the advantages of real-time reconnaissance and repeatedly revisiting the key hotspots, etc,so study on squint SAR real-time processing is very meaningful. The main contents are as follows:1. The squint SAR geometry model is analyzed according to the features of large range walk and two-dimensional coupling of range and azimuth. The range model and echo model of a point target are achieved, and the analysis of the slant model error, distance migration error and two-dimensional coupling error is given, and then the selection method of focus algorithm is presented; Secondly, the types and influencing factors of motion error are introduced, and then the method of parameter estimation and compensation is given; Finally, the geometric correction principle and projection methods are analyzed, and combined with engineering application, the high squint SAR imaging algorithm flow is given.2. The efficient parallel processing theory is studied according to the features of complex algorithms and hard real-time in the squint SAR. It describes the parallel processing performance of the speed-up ratio and parallel efficiency and several factors. In view of radar signal processing in parallel, this paper emphatically analyzes the selection of parallel processing units, topology of the system as well as task allocation method. And then the parallel processing architecture is presented to adapt to the practical application.3. The real-time signal processing technology based on parallel TMS320C6678 is studied. Firstly, the TMS320C6678 chip are described in detail, and the data storage and direct data access technology(DMA) are discussed; Secondly, it gives focus on the topology of the squint SAR parallel real-time signal processing system, multi-core synchronous communication mechanism, task allocation algorithm and mapping; Finally, the fly experiment results are achieved and they verify the correctness and effectiveness of SAR parallel imaging design.