Sar Imaging Simulations Based On The Ocean Scenes And The Electromagnetic Scattering Study

Since the beginning of 1976, with Mandelbrot series of fractal book published, fractal theory has aroused the concern of the global scientific community and immediately reflected in many fields of science. Fractal theory provided a simple and practical tools to describe and analyse the nature and formation complex mechanism and get the attention of many industries and applications.Complexity of the electromagnetic scattering of the rough ocean surface scene has always been a concern point, due to global and local self-similar, while each part can be increased as the similarity of the whole, in the rough ocean surface scattering studies the fractal theory naturally is used. The multi-path of the surface electromagnetic scattering about the ocean clutter has a certain significance; while on the waves, currents, internal waves given a certain interpretation of the physical phenomena; to some extent, promoted the developments and applications of the oil spill, surface ships and other marine SAR monitoring.In recent years, marine scientists are beginning to utilize the fractal method to the ocean modeling and the ocean waves spectral analysis. The first chapter will give a brief analysis of the current situation and the significance, moreover the paper's content and innovations were introduced. The second chapter is the fundmental of the SAR image simulation and the scattering of electromagnetic waves analysis. First a brief introduction about the main parameters of the synthetic aperture radar remote sensing applications was given, then introduced the Kirchhoff approximation method, and using the stationary phase method deduced the geometrical optics solution, then according to the Maxwell equations, derived the electromagnetic wave polarization elliptic equations. Finally, using the polarization sphere and Stokes matrix, for the representation of the target's scattering polarizantion, discussed the scattering matrix of the single station and the bistatic transceiver.The algorithms for generating Spaceborne SAR raw signals are explored. A time domain method of the simulating SAR raw target signals is presented firstly, which can simulate accurately raw dates but burdens upper computational complexity. Therefore, a frequency domain method with lower computational complexity is also proposed.Based on the theory of Kirchhoff approximating and the model of Franceschetti facet field simulating, an algorithm for the computing the facet backscatter coefficients is presented. Especially, the second part of the computing the backscattered field is given.The desired signals of point targets, point array targets and three-dimensional targets are simulated and analyzed respectively. The simulating results show that the methods proposed can estimate correctly the SAR characteristics.