Sliding Bunching Sar Imaging Mechanism Research

SAR has traditionally operated in either the strip-map mode or the spotlight mode.In the strip-map mode, continuous imagery is generated, the resolution being limited tohalf that of the real antenna length due to the difficulty of increasing the length of thesynthetic aperture. In the spotlight mode, longer synthetic aperture is generated, andconsequently higher resolutions can be achieved. But the system illuminate only alimited area on the ground. The Sliding Spotlight model described in the article can geta better resolution than strip-map mode and better observed area than spotlight mode.by steering the antenna on a point further away from the radar than the area beingilluminated which can be regarded as coming from the underground. By doing this, thismode can get good combination between the resolution and observed area.(1)Describe the spatial geometry of the sliding spotlight mode and the echocharacteristics, analyze the Doppler characteristics, resolution and the bandwidthparameters.(2)Analyze the difference and the conversion among the strip-map, spotlight andthe sliding spotlight mode. Define the critical sliding factor to choose the proper slidingfactor for the best azimuth resolution and the width.(3) Analyze the deramp way to deal with the azimuth aliasing problem in slidingspotlight mode, use the Range Doppler algorithm based on secondary rangecompression algorithm, CS algorithm, and the Wave Number Domain algorithm toprocess the signal process the signal, accomplish the simulation, to verify the validity ofthe algorithm.