Orbit target IR model can be used to design orbit target detection sensor, generating simulation data to validate the data processing algorithms, such as the target detection and tracking. In the work, a novel orbit target IR model is built. IR detection uses the difference between the target and the background to achieve the target effectually. In order to increase the application ability, the IR model consists of the orbit target and the celestial background. The geometry module and IR radiometric module make up the orbit target IR model. The professional geometry modeling software CAD is used to build the geometry model. The reflection between the subassembly is considered in the radiometric, because the thermal control coat of the satellite (such as optical solar reflector) has very high specular reflectance generally. The Midcourse Space Experiment (MSX) catalog is used to calculate the IR celestial IR background. The IR radiation provided by the MSX is used to calculate the equivalent temperature and the observation angle by the SPSO (Stochastic Particle Swarm Optimization) method. The transfer algorithm adopted in this paper is compared with the Monte-Carlo method, and the results show that the relative deviation between them is less than 10%.
Infrared thermal imaging technology uses the detector to receive infrared radiation from the measured object, and the object temperature distribution will be changed into a visual image by signal processing system. The accuracy of measuring temperature will be affected by the surface emission rate, reflectivity, atmospheric attenuation, and background radiation and environmental effect under normal temperature and pressure conditions. In order to realize the accurate temperature measurement under the condition of ultra-high vacuum and cryogenic environment, the general formula of the theoretic temperature of measured object surface is deduced, which based on the principle of thermal radiation and temperature measurement by infrared thermal imager. In this paper, the impact factors of temperature measurement accuracy of long-wave infrared thermal imaging system under those conditions are analyzed, and various theoretical numerical value of factors are plotted on the curve of precious accuracy temperature measurement. The results of analysis for the thermal imaging system will improve temperature measurement precision in vacuum thermal test, which have active practical significance.
The purposes of spacecraft vacuum thermal test are to characterize the thermal control systems of the spacecraft and its component in its cruise configuration and to allow for early retirement of risks associated with mission-specific and novel thermal designs. The orbit heat flux is simulating by infrared lamp, infrared cage or electric heater. As infrared cage and electric heater do not emit visible light, or infrared lamp just emits limited visible light test, ordinary camera could not operate due to low luminous density in test. Moreover, some special instruments such as satellite-borne infrared sensors are sensitive to visible light and it couldn’t compensate light during test. For improving the ability of fine monitoring on spacecraft and exhibition of test progress in condition of ultra-low luminous density, night vision imaging system is designed and integrated by BISEE. System is consist of high-gain image intensifier ICCD camera, assistant luminance system, glare protect system, thermal control system and computer control system. The multi-frame accumulation target detect technology is adopted for high quality image recognition in captive test. Optical system, mechanical system and electrical system are designed and integrated highly adaptable to vacuum environment. Molybdenum/Polyimide thin film electrical heater controls the temperature of ICCD camera. The results of performance validation test shown that system could operate under vacuum thermal environment of 1.33×10<sup>-3</sup>Pa vacuum degree and 100K shroud temperature in the space environment simulator, and its working temperature is maintains at 5℃ during two-day test. The night vision imaging system could obtain video quality of 60lp/mm resolving power.