Airborne SAR Raw Signal And Image Simulation

Synthetic aperture radar(SAR), which has many advantages such as high resolution.Airborne SAR raw signal simulation and image simulation play an important role in the development of whole airborne SAR system. Airborne SAR raw signal simulation and image simulation obtained by simulation technology is hope to be able to approach the real raw signal data and image, this thesis launched research work based on this point, the major work and contents of this thesis are as following:(1) Analyzed the synthetic aperture principle of SAR, the work process of how to obtain the high resolution, and the characteristic of the raw signal, and researched the imaging process of how to obtain SAR image by raw signal.(2) Studied the methods of SAR raw signal simulation, with the basic theory of airborne SAR raw signal simulation as a starting point, researched a fast time domain simulation method based on the traditional time domain simulation method. In view of the disadvantages of large amount of time domain simulation method to calculate, frequency domain simulation method can satisfy the requirements of real-time, studied the simulation method based on I omega K, compared with the traditional frequency domain simulation, this method can simulate the range migration, so we can obtain a more accurate raw signal, finally, gave the simulation results of some point target and area target used the methods of time domain simulation method and simulation method based on I omega K.(3) Studied the raw signal simulation and imaging under the situation of trajectory deviations, based on SAR motion error model, analyzed the raw signal and phase error under the situation of trajectory deviations, which caused the Doppler rate estimation error, so used MD algorithm to estimate the Doppler rate under trajectory deviations, finally we present the simulations results of raw signal simulation of trajectory deviations and Doppler rate estimation using MD algorithm simulation imaging results.(4) According to the requirements of project I participated, researched the ultra-wideband(UWB) SAR signal, UWB SAR signal can get higher resolution. First studied the synthetic bandwidth technology, which through launch stepped frequency signal using the synthesis technology to obtain wideband signal, improve the resolution. In addition to reduce the sampling rate use stretch method to decrease the bandwidth before signal processing, and studied the resolution and SAR imaging algorithms after stretch processing. Finally gave the simulation results of synthetic bandwidth and SAR imaging simulation results after stretch processing.To sum up, this article mainly around the image of SAR used raw signal simulation, studied raw signal simulation method, and researched the situation of trajectory deviations and ultra-wideband signal raw signal simulation and imaging.