Research On The Millimeter Wave Radiation Signal Simulation And Recognition Technology Of Armored Target

In a conventional war,a tank has been dubbed “King of the Land Warfare”,because of its powerful direct fire,high cross-country mobility and strong armor protection,and has always been the most powerful weapon in the ground wars.To prevent large-scale clusters of tanks,a variety of anti-tank weapons came into being.Passive millimeter wave detection technology can identify the armored target on the ground by using the difference between the background and the metal in the millimeter wave band,so it is widely used in all kinds of airborne,missile-borne anti-tank weapons.The research background of this dissertation is the application of millimeter wave radiometer in the anti-tank weapon system,so the author systematically studied the millimeter wave radiometer on the ground armored target detection and identification of key technologies.The main contributions and innovations of this dissertation are summarized as follows:(1)For “unstable fluctuation” of armored target antenna temperature curve,this dissertation established the geometric model of T59 tank and M1A1 tank,using the combination of Pro/E Wildfire 5.0 and ANSYS.On this basis,the ray propagation analysis method and the multiple inverse rays tracing method of radiation temperature were proposed,and the calculation model of the armored target antenna temperature was established.In traditional modeling method,armored target was equivalent to a planar metal target.Comparatively,this dissertation set up a three-dimensional and multiple reflections radiation calculation model based on an armored target entity.(2)In terms of the “non-uniformity” of the background radiation temperature,the background apparent temperature statistical model was established with the chi-square goodness of fit test method,the apparent temperature distribution of the background under the specific detection condition was obtained.At the same time,the least-square fitting model of background apparent temperature was established with the data fitting method,and a fitting formula of background apparent temperature with incident angle and environmental temperature was obtained.In addition,the cubic spline interpolation model of background apparent temperature was established,and a smooth curve which went through all the sampling points was obtained.(3)Based on the antenna temperature calculation model of armored target and apparent temperature model of background,the millimeter wave radiation temperature calculation method and model whose target reconciled with background was put forward.In this model,the detection process of the armored target was simulated systematically,and the antenna temperature curve was consistent with the measured result.(4)The characteristic parameter of armored target was proposed,which was based on the stereo effect rate and stereo effect standard deviation.The parametric analysis showed that the armored target had a significant stereo effect compared with background and other planar targets.Meanwhile,it further explained that the necessity of this dissertation modeled on armored target entity,and limitation of the traditional modeling method in which armored target was equivalent to a planar metal target.(5)An armored target recognition algorithm was proposed,which based on the complexity of the radiation temperature and the entropy of the radiation temperature,and according to the theory of target detection,a recognition algorithm performance evaluation system,which based on the recognition probability,false probability and miss probability was established.Results showed that compared with the traditional threshold,the recognition algorithm in this dissertation obtained a higher recognition rate on armored target,while it also reduced the probability of misidentification the other "pseudo-target" as the armored target,and it had advantages of small computational complexity,good real-time performance,simple algorithm and easy engineering realization,etc.(6)Based on the background radiation model,the armored target radiation model,the antenna model,the intersection model and the target recognition algorithm,a detection signal simulation and recognition system of armored target which detected by the millimeter wave radiometer on bomb were established.The millimeter wave radiation signal of armored target in different simulation conditions,including different tank targets,different ground backgrounds,different environment temperature,different radiometer antenna,different intersection conditions,different detection angle,and et al were simulated comprehensively and systematically.By comparison with the measured data,it was showed that the simulation system in this dissertation got the detection signal of armored target under various conditions truly and accurately,and made an accurate determination whether the target was armored target through the recognition algorithm.The research purpose of this dissertation was to detect and to recognize the armored target with millimeter wave radiometer on bomb,based on the different radiation characteristics between armored target and background,with the means of realizing software simulation,and according to recognition algorithm criteria.It realized the effective detection and recognition of armored target with millimeter wave radiometer on bomb,and provided a simulation platform and a technical approach for the detection and identification of ground targets with millimeter wave radiometric characteristics.