A Unified Multimode SAR Raw Signal Simulation Method Based on Acquisition Mode Mutation

Raw signal simulators for synthetic aperture radar (SAR) in different acquisition modes have been studied individually. This letter is dedicated to presenting a method for simulating multimode SAR raw signal in a unified framework. To this end, we first simulate stripmap SAR raw signal, and then mutate the raw signal from stripmap mode into the desired acquisition mode. The acquisition mode mutation is implemented by azimuth-time-variant and range-frequency-dependent bandpass filtering. While processing in range-frequency domain brings forth high accuracy, processing in azimuth-time domain makes the method applicable for flexible antenna steering laws specified by multiple SAR acquisition modes, such as staring spotlight mode, sliding spotlight mode, and terrain observation by progressive scans mode. The proposed method is validated by the simulation results.

I. Introduction

Raw signal simulators for synthetic aperture radar (SAR) are useful tools for the development of SAR systems, innovation of imaging formation algorithms, educational purposes, and so on. As different SAR acquisition modes have been proposed, such as stripmap mode, terrain observation by progressive scans (TOPS) mode, staring spotlight mode, and sliding spotlight mode, study on multimode SAR raw signal simulation draws wide interest. Raw signal simulators for different SAR acquisition modes have been studied individually [1]–[4].