Study On Modeling And Application Of Target Optical Characteristic

The dissertation is supported by a number of National Defense Advanced Research Foundation, The main work and the results of this paper are as follows.Base on analyzing of the basic theory of artificial neural network, a method is presented for building Bidirectional Reflectance Distribution Function(BRDF) model with BP neural network.2D and 3D BRDF models for various materials on laser band and a BRDF model with wavelength parameter for a certain material are built. It turn s out the neural network modeling has the advantages of high accuracy, wide application, and etc.In view of the targets coated by multi-material, the models containing material information are made and a new visualizing-calculation method is presented. A software package for calculation optical characteristic of the targets coated by multi-material is designed and completed. The Laser Radar Cross-Section (LRCS) distribution curves of a large number of targets in the air and on the ground are obtained, with the results analyzed and discussed.The back LRCS distribution curve with the angle of a target drone with serious paint stripping is measured. The LRCS of the target is obtained with the paint stripping of the surface simulated with Monte Carlo method to estimate the seriousness of the paint stripping.A study of the scaling relationship of complex target is made based on scaling theory and measurement. The scaling theory and calculation method are proved by analyzing of results of scaling model measurement and full size model calculated of air targets, such as F16.It is emphasized that the error (absolute values) between calculation and measurement of scale model remains unchanged in the full size model.The radiation and scatter characterizes of the target and sea-sky background and atmospheric transportation characterizes are analyzed. An infrared image simulation system of sea-sky background is designed and completed. A lot can be done with the system, such as the calculating of solar radiation,sky-sea background radiation,and transmissivity of atmospheric, the modeling of target and sea surface,and the scattering of background radiation from target and sea surface.The output form includes infrared simulation image, data file, and curves.