Research On The Effect Of Detection Condition And Atmospheric Environment On MRTD Of Infrared Thermal Imaging System

In recent years, the infrared thermal imaging system is widely used in the field of military and civilian. The performance evaluation of infrared system is accompanied with the development and application of the whole infrared system. Therefore, people pay more attention to the performance evaluation of infrared system.In this paper, by comparing the different methods of performance evaluation of the thermal imaging system, The MRTD model is chosen as the main model. The influence of the atmospheric environment and the detection conditions on the MRTD of the infrared thermal imaging system is studied. Because of the complexity of the atmospheric environment and the detection conditions will also be changed under different atmospheric conditions, It is difficult to calculate the MRTD of the system under different atmospheric conditions.MODTRAN is widely used in the field of target detection. Atmospheric transmittance of the atmosphere can be calculated in different atmospheric modes, different atmospheric components and different sounding paths by MODTRAN. How to apply the atmospheric transmittance data calculated by MODTRAN to MRTD integral model is the key problem to be solved. Detection wavelength range can be divided into a series of narrow bands using spectral bisection method. Fristly, the atmospheric transmittance of each narrow band is calculated using MODTRAN and establish the corresponding data table. Secondly, the integral model of MRTD is changed into the summation model and the MRTD is calculated by using the data of the atmospheric transmittance in the data table. In this paper, two types of thermal imager are used to calculate the MRTD under different conditions, such as different target, atmosphere environment, level of detection, detection probability and so on. The atmospheric transmittance and the MRTD values of the infrared thermal imaging system under the condition of sunny day, different humidity, rain, different height and different detection angle were analyzed.