Research On Spaceborne SAR Scattering Modeling And Raw Signal Simulation

Spaceborne Synthetic Aperture Radar (SAR) is a all-day and all-time high resolution microwave imaging radar, and it is widely used in the area of the national defence, the economy, the scocity and so on. Under the background of the distributed spacebone SAR system, the geometry modeling, the scattering modeling and raw signal simulation of spaceborne SAR is studied, which is the important research aspect of InSAR (Interferometric SAR) and GMTI (Ground Moving Target Indicator), and has huge pratical value.The geometroy modeling in the raw signal simulation of spaceborne SAR includes the spaceborne SAR space geometroy modeling and the spaceborne SAR scene geometroy modeling. By using different space coordinate and orbit model, the position of aperture phase center of SAR antenna can be calculated exactly. The land scene and ocean scene is studed in the spaceborne SAR scene geometroy modeling, which is the typical representative of static scene and dynamic scene respectively. The spaceborne SAR scattering modeling studies the interaction between electromagnetic wave and scene, and decides the quality of the simulated SAR images. Three types scene scattering modeling is studed based on different object: land scene scattering modeling, ocene scene scattering modeling and military target scattering modeling based on RadBase software. The spaceborne SAR raw signal simulation is the basic of the spaceborne SAR system design; it computes the spaceborne SAR raw signal according scattering properties, formation paramenters and radar system paramenters.The spaceborne SAR raw signal simulation has two algorithms: the time algorithm and the spectral algorithm. The time algorithm is the most exact method, but it costs too much time and is not capable of rapid raw signal simulation of huge scene; on the other hand, the spectral algorithm reduces the algorithm time enormously by reasonable approximation, which makes huge scene and multi-satellites SAR raw signal simulation come ture.At last, a spaceborne SAR raw signal simulation software package is done due to the above reseach, which can simulate the raw signal of point target, DEM data and ocean scene.