A Study On Simulation Methods For Imaging With Brightness Temperature Radiation In Scenarios With Rough Surfaces

Simulation imaging based on brightness temperature radiation is an indispensable step in the development of new sensor systems.Also,it is an important research direction for passive microwave remote sensing.These simulation images are helpful to analyze radiation characteristics of the detected targets in different scenarios,to understand various radiation phenomena and to recognize specific radiation patterns.By comparing the simulated image with the measured,we can judge the merits of the actual measurement results and quickly evaluate the performance of the imaging radiometer.Therefore,simulation imaging has a certain guiding role in the design and improvement of the radiometer system,which provides an important approach to further study of the ground objects by using microwave radiometer.In this thesis,the simulation method of brightness temperature radiation is studied in the following three aspects:1.Simulation imaging for the smooth surface scenario based on space meshing brightness temperature tracing method(SMBTTM)is presented,which avoids intersection tests between rays and object facets and improves the efficiency of calculation.By comparing with measured images of radiometer and the traditional method,the imaging results verifies the correctness and effectiveness of SMBTTM.2.Various factors affecting the simulated images are considered in the maritime targets and three-dimensional(3D)geometry scenario,such as ray interval,polarization mode,media characteristics of targets,observing pitch angle,antenna smoothing and ray reflecting times.It is shown that the radiation simulation imaging is of great significance to assessing the performance of radiometer system.3.Rough surface model for scene simulation is presented in order to obtain the simulated images of the airport runway and 3D geometry scenario.The results indicate that the model for rough surface can distinguish targets of different roughness,improving the discrimination of the brightness temperature tracing method.In addition,the effects of different root mean square(RMS)height,correlation length of the same medium and different salinity of sea water on brightness temperature are studied and analyzed.