Research On Data Transmission And Processing Of Short Range Millimeter Wave Imaging System

The millimeter wave,located between the microwave and the far infrared wave in the electromagnetic wave,has characteristics of them both.Millimeter wave has a certain penetrability,and it can penetrate clothes to detect hidden objects.Besides,millimeter wave is not ionized.Compared with X ray imaging,millimeter wave imaging does no harm to human body.Based on the above characteristics of millimeter wave,millimeter wave imaging technology has broad application prospects in the field of security inspection.This paper is based on the actual project requirements of the Institute of electronic engineering,Chinese Academy of Engineering Physics,aiming at improving the imaging efficiency of short range millimeter wave security imaging system,some key problems of the millimeter wave security imaging system are studied.The main work is as follows(1)Aiming at the problem of high packet loss rate in real-time transmission of millimeter wave security imaging system,a high-speed data reception scheme based on WinPcap is presented.The scheme adopts dynamic memory pool technology based on cyclic queue and multithread design method to reduce data transmission packet loss rate.Test the packet loss rate of data transmission,compared with the traditional direct data receiving,the packet loss rate of data reception has been reduced to a certain extent,and meets the data transmission requirements of the millimeter wave imaging system.(2)The difference between millimeter wave security imaging system and traditional SAR imaging system is analyzed.According to the characteristics of the millimeter wave imaging system,the Range Migration(RM)algorithm based on the frequency domain and the backward projection(Back Projection,BP)algorithm based on the time domain are introduced.The feasibility of the algorithm is verified by the simulation analysis of the two algorithms.(3)Aiming at the low efficiency of RM algorithm under the traditional CPU platform,two parallel acceleration methods of RM algorithm based on GPU are presented.The simulation data and the measured data are tested,the two methods presented in this paper achieve 10.05 and 8.23 times speedup respectively under the premise of guaranteeing the imaging quality,which meets the fast imaging requirement of millimeter wave security imaging system.