New Technology And Out-field Experimental Research On MIMO Radar Imaging

MIMO radar is a parallel multichannel mechanism by using multi transmitters multi receivers and it can form far more observation channels than the number of antennas and far larger virtual aperture than the transceiver array.It has a higher imaging resolution than a real aperture radar.At the same time,multi channel acquisition of space target information is implemented in parallel,and space targets'information can be collected at a single time.Information has better real-time performance than SAR imaging.However,in the MIMO radar imaging experiment,the complex application environment,such as the large scene target and the influence of the environmental noise,is usually faced.For the MIMO radar system,the imaging pressure will increase when the imaging ability of the system is limited to the number of observation channels,and the imaging effect can not reach the expected target.By increasing the number of antennas to improve the imaging capability of the system,the system cost will be greatly increased,and the system structure needs to be adjusted.In addition,although the MIMO radar imaging technology has made great breakthroughs,the experimental research of MIMO radar imaging is rarely carried out,and most of them are under ideal conditions in the microwave anechoic chamber.In order to make the MIMO radar imaging technology become more practical,it is very important to study the out-field experiment and the out-field experiment has different experimental environment under ideal condition.Under the different experimental environment,the uncertainty in the experiment will deteriorate the results of the imaging experiment in varying degrees,so it is of practical value to solve the problem of the influence of the MIMO radar out-field experimental environment on the imaging results.This dissertation mainly focuses on the above problems.The first research content of this dissertation is about the new technology of MIMO radar imaging.First,a MIMO radar imaging method based on strip segmentation is proposed to solve the problem of limited imaging capability of radar system in large scene.This method is mainly based on MIMO radar imaging under the condition of large scene and complex target.The method also involves stripe band sampling and single stripe image stitching to achieve the final large scene imaging.This method can improve the imaging quality and improve the imaging effect without increasing the system cost and imaging time.The second part is an imaging optimization method based on imaging surface correction,which is based on the uncertainty of the radar experiment scene.This method uses the spatial spectrum theory to analyze the imaging error and builds the imaging surface correction model,and proposes an algorithm for the image surface correction.The target location offset caused by external factors is used to correct the imaging plane,and corresponding simulation experiments are designed to verify the effectiveness of the method.The second content of this dissertation is the research of MIMO radar imaging out-field experiment.With the help of the distributed radar system,the MIMO radar imaging experiment scheme is designed.The experimental scheme mainly includes the design of the transmit signal form and the layout design of the transceiver array.The experiment was carried out under the guidance of the experimental scheme.And the data processing includes the use of the acquired scene position information and the transmitting signal to calculate the spatial spectrum support area.Then the echo is filtered to remove the noise,and the matched filtering is used to obtain the different channel information.Then obtaining spatial spectral values after the correlation processing and sampling,and the target imaging results are retrieved by the spectral support area and the spectral value inversion.The imaging error correction method based on image plane correction is used to verify the experimental results,and the optimized imaging results are obtained.This dissertation mainly aims at the problems that may exist in the practical application of MIMO radar.In view of the related research on the complex target of large scene and the disturbance of the external environment,the corresponding analysis model is established based on the spatial spectrum theory.It is verified by the simulation experiment and the actual experimental data processing.It is practical for the MIMO radar imaging technology.It has some guiding significance.