Research On Radiation Characteristics Analysis And Parameter Estimation Of Midcourse Ballistic Target

Ballistic midcourse is the key stage of target identification and attack in missile defense system.With the continuous development of missile penetration technology in various countries,multiple fake targets are released in the midcourse,which brings great difficulties for defense to identify.Space-based infrared system is the main working system of midcourse target recognition.Analyzing infrared radiation characteristics of target and extracting its features are the basis of target recognition.From the perspective of infrared radiation,this paper adopts the method of combining theoretical analysis and simulation experiment to analyze the infrared radiation characteristics of the ballistic mid-course target,and estimates some parameters of the target.The main research contents of this paper include the following aspects:(1)According to the movement law of space targets,the trajectory movement model of ballistic targets is established,and the flight attitude and space position of the whole mid-course process are obtained by simulation,and the variation of each radiation Angle coefficient during the flight of the target is calculated.Then the heat balance equation is established and the temperature change sequence is calculated.Finally,the temperature distribution is used to calculate the radiation of the target itself,and the bidirectional reflection distribution function model is used to simulate the radiation of the target surface reflected by the sun and the ground.The irradiance of the target at the entry pupil of the detector is obtained by superposing its own radiation and reflected radiation.(2)By changing the target parameters in the middle section,including physical and motion parameters,the change rule of its irradiance sequence was analyzed.Based on the difference of irradiance between target and decoy at space detector,the features that can be used to distinguish them are extracted.The characteristics of infrared heat,irradiance,heat capacity and micromotion are analyzed and demonstrated.(3)Based on the target radiation sequence and extracted characteristics,the target is estimated from two aspects of material parameters and micro-motion parameters.The target temperature and thermal radiation area are estimated according to the principle of thermal radiation.The least square method is used to estimate the precession frequency and amplitude of the micro-motion of the target,and the results are reliable within a certain error range.