Research On Irradiance Simulate And Measurement Of Infrared Target Simulator

Infrared target simulator is an important part of hardware in the loop simulation system of infrared homing weapons; it can provide sufficiently realistic infrared targets and physical properties of scenes, which including spectral range, irradiance size, characteristics of movement. The performances of simulator directly affect the accuracy of simulation.The most important performances was the irradiance at exit pupil of the simulator. To ensure the performances, it must be test and calibrate the irradiance at exit pupil. As the minimum irradiance at exit pupil of infrared target simulator is 10-10W/cm2, and the dimensions of the measuring devices are strictly limited, it is resulting in difficulty in measuring. Therefore, it is necessary to develop a special measuring instrument of infrared radiation for the simulator. So the instrument should check and calibrate the irradiance at exit pupil of the simulator regularly Existed on irradiance simulation and measurement methods of the infrared target simulator at exit pupil, the paper was completed for the following areas:The paper combines the working principles and performance parameters of infrared target simulator, and then derives the irradiance transfer model. The mathematical model should reflect the various factors in the course of irradiation transfer, including the changes in the field diaphragm opening, the solid angle of radiation sources, the transmittance of optical system, and atmospheric attenuation. Combining with the technology indexes of simulator, the paper designs the light source and the field diaphragm optical of the simulator. According to the demonstration of the the overall program, this article proof that this design scheme should meet the technical requirements.This paper analyzes the principle of irradiance measurement, designs the overall scheme of measuring instrument. At the minimum irradiance value is 10-10W/cm2, the signal to noise ratio in 1~3μm and 3~5μm spectrum of the measuring instrument are calculated, they are all greater than 100. Blackbody reference source with built-in way could eliminate the background radiation on the measurement results. As the measuring range is broad, and is from 2.0×10-10W/cm2 to 8.0×10-4W/cm2. This article adds three attenuation pieces in the light path, in order to achieve 1000 times attenuation to the signal. This paper adds Measuring lens optical system by adding Shift lens to increase the axial dimension, so that could make the modulation plate instal easily. It is parallel in the center of shift system, so that the flat glass components as spectral filters and attenuation are easily to install.Accurate calibration is crucial to ensure accuracy. This paper analyzes calibration methods for infrared irradiance, designs three calibration programs, and considerates the laboratory conditions and the advantages and disadvantages of each program, finally determines the reasonable calibration program. The paper also analyzes the errors introduced during calibration, then combines with the theory of uncertainty, finally calculates the measurement uncertainty of measuring instrument was 3.16%, less than 10% of the required technical specifications. The paper describes the impact factors in the process of measurement and the corresponding solutions at the end.