Research On The Echo Simulation Algorithm For Bistatic SAR

Bistatic SAR (Bistatic Synthetic Aperture Radar) whose transmitter and receiverare located at different platforms is a new kind of radar. It has the advantages ofobtaining richer information, anti-electronic jamming, anti-destroy, anti-intercept andbecomes a hot topic in the field of radar imaging currently. This dissertation focuses onraw echo simulation algorithms of bistatic SAR, and the main works are summarized asfollows:1. An echo simulation algorithm based on equivalent scatterer of bistatic SAR isproposed. Aiming to the one-dimensional Fourier transform algorithm, the calculationof SAR system transfer function is simplified and the efficiency of echo simulation fornatural scene is improved. The principle of the algorithm is analyzed, the formula of anequivalent scatterer’s coefficient is derived, and the processing steps and flow chart areintroduced. The echo simualtion results of bistatic SAR under shift-invariant andshift-variant mode verify the effectiveness of this algorithm. And the effect of rangeapproximation on echo simulation is analyzed from the viewpoint of error.2. An echo simulation algorithm based on inverse imaging processing for bistaticSAR is presented. On the basis of using two-dimensional principle of stationary phaseto obtain the two-dimensional spectrum of bistatic SAR echo signal, combined with theinverse processing of RD imaging, the fast echo simulation for shift-variant bistaticSAR is achieved. The echo simulation results of point target and natural scene indicatethe validity of the algorithm.3. An echo simulation algorithm based on two-dimensional frequency domain forshift-invariant bistatic SAR is proposed. The bistatic SAR echo is characterized by theconvolution of ground scattering coefficients with the transfer function of bistatic SARsystem. The express of the transfer function for shift-invariant bistatic SAR system isdeduced, and its spectrum is represented as the product of the spectrum of the referencepoint and the space-variant fuction under the narrow beam approximation. So the fastecho simulation is carried out through two-dimensional FFT. The processing steps andflow chart are introduced, and the simulation results of point target and natural scene validate the effectiveness of the algorithm.4. The performance such as efficiency, accuracy and the difficult of motion errorsimulation of the above-mentioned three algorithms are analyzed and compared. Theadvantages and disadvantages and the scope of application of those algorithms areanalyzed in detail.