Study On Imaging Method And Experiments Of The Target Using Full-polarized Microwave Radiometer

The microwave radiometer imaging technology has adopted in very wide range fileds,such as security check、navigation、blind landing、remote sensing and so on. The microwave radiometer is passive remote sensing device that is harmless to human body,so it has great advantage in scanning human body. The full-polarized microwave radiomete can get 4 ploarized parameters of target which are called Stokes parameters vT 、hT 、3T 、4T. More infomation can accessed about human body with the 4 polarized parameters that makes the full-polarized microwave radiometer’s application in medicine and security possible. The thesis utilize a solution to ploarimetric microwave radiometer scanning imaging to analyze human radiation image.Firstly,microwave radiometry theory is introduced to set up the theory fundation of full-polarized microwave radiometer scanning imaging. The theories include Planck’s law、antenna temperature、Stokes polarized parameter.Then the full-plorized microwave radiometer scanning imaging system is introduced in detail. The system includes three parts: scanning module, full-polarized microwave radiometer,Software. Scanning module consists of scanning platform and motor driver. The motor driver is controlled by software to drive scanning platform which carries the full-polarized microwave radiometer to move. The full-polarized microwave radiometer is Direct correlation polarimeter, the correlator is digital correlator. Software consists of motion control part, data analysis and reception part, imaging part which is developed by Visual Basic language. Motion control part control the motor driver by RS-232 to USB port so that motor can drive the sacnning platform to move in complex and subtle type. Data analysis and reception part can access microwave radiometer output voltage, and parse the data based on data-packet format to display the data and save the data on the disk. Imaging part combine the data of coordinate and microwave radiometer output voltage data to form brightness temperature of vT and hT,and save all four channel data so that we can analyze later.Then analyze the important factors that have important influence on image quality. The important factors include spatial resolution、scanning distance、scanning speed、residence time、sample rate. These factors influent interactively. Spatial resolution is determined by microwave radiometer antenna and scanning distance. Residence time means time of antenna passing through the spatial resolution, which is determined by spatial resolution and scanning speed. sample rate is also very important factor, which is too less to get incomplete information and is too much to get much redundant data.Finally,the imaging simulation under far-filed will discussed. And the twodimension scanning imaging test with the Polarimetric microwave radiometer of 37 GHz gets the different body radiation images with vT 、hT 、3T 、4T polar information will be presented.