Research On The Electromagnetic Scattering Calculation Of Typical Targets In Time Domain And The Fast Algorithm

With the great development of the modern remote sensing, the resoluti on ofSAR has been improved a lot. Research and implementation of simulation systembased on high-resolution SAR echo data play a great important role on the designof SAR system, imaging algorithm, geometric distortion correction and researchof high-resolution SAR image. The approximation of the ideal target isimplemented in the traditional echo simulation algorithm and the backscatteringcoefficient is got by the artificial settings. As a result, the simulation of the realand non-ideal target cannot be efficiently simulated and the requirements of high-resolution and high-precision SAR cannot be satisfied.In order to provide the accurate scattering characteristics of the typicaltargets’ imaging points for the high-accuracy SAR system, the Finite-DifferenceTime-Domain(FDTD) is mainly researched in this paper. And based on this, theresearch on the implementation of FDTD in the SAR target echo simulation iscarried out.FDTD has the advantages of simplicity and second-order accuracy. However,the discretization of time and space of FDTD is affected by the constraints. In caseof high-frequency and electrical large-scale structure, there is a heavycomputation burden using FDTD. So the parallel time domain electromagneticmethod of parallel computing which is based on the wavelet theory, the method ofmoments domain multiresolution technique (MRTD) and also based on the MPIand Open MP is studied and is implemented in the SAR echo simulation in thispaper. And that will reduce the computing time with the same or higher accuracy.The former is combined with the wavelet theory and the MRTD on the algorithmto discretize the Maxwell equations, the computation calculation is reducedcomparing with the traditional FDTD. And the latter is focused on increasingcalculating cells and expanding the storing resources to increase the speed ofcomputation.Furthermore, after the comparison with the traditional FDTD and the evaluationof the quantitative and qualitative experimental results, the algorithm proposed inthis paper is applicable in SAR echo simulation and it has great effectiveness in improving the computation speed. The method researched in this paper haspractical significance and value in high-resolution and high-precision SAR echosimulation.