Infrared thermal imaging technology receives infrared radiation from the measured object, and the temperature distribution will be changed into a visual image by signal processing system. In order to verify the accurate measurement, the temperature measurement experiment under vacuum environment was carried out by constructing the low temperature standard blackbody radiation source, which temperature range was from -80°C to +100°C and temperature control stability was better than ±0.05°C/30min. The general formula of the theoretic temperature of measured object surface is deduced under ultra-high vacuum and cryogenic environment, which was based on the principle of thermal radiation theory. The capability of long-wave infrared thermal imager was verified from -40°C to +60°C. The static characteristics of measurement accuracy, repeatability and linearity were analyzed, and the dynamic measurement characteristics were also tested. The results were compared with the fine thermocouple measurement data.
The color deviation, which refers to the different between the obtained image and the image under the standard light, is from the light source and reflection characteristic of the object. For satellite remote sensing, the length of the radiation transmission path is different for imaging of different latitudes, especially considering the effects of the atmosphere. Therefore, imaging for high latitude in the winter maybe brings some color deviation into the data. There have some color deviation detection methods for digital camera photo, but they are not fit for the remote sensing data, because of the large image range. In the work, a color deviation detection method for the satellite remote sensing image is developed. And the method is validated using the Landsat 8 images obtained in the winter and summer respectively.
Orbit target IR characteristic is the basis of the IR imaging detection equipment design, the corresponding digital simulation model validation, and the application processing development, such as the target detection and tracking. In the work, an infrared measurement system for simulated space target is represented. The system can acquire the infrared characteristics of the target in the simulated space environment on the ground. In order to simulate the whole orbit environment, vacuum chamber and solar simulator are used in the work. An IR window is developed for the system. Then measurement instruments can be place outside the chamber to get the characteristic through the IR window. The work also provides a method to calibrate the IR window. The IR characteristic at the wavelength range of 3 μ~12 μm can be obtained with the system.
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%.
FOV separation (between VNIR sensor and SWIR sensor) and motion compensation imaging modes are introduced into the pushbroom imaging spectrometer to increase the SNR of the imaging data sometimes. Besides the higher SNR, the two imaging modes result in some bad effects on the imaging data, such as the additional misregistration. In the paper, a digital simulator for pushbroom Offner hyperspectral imaging spectrometer is used to analyze the misregistration caused by the FOV separation and the motion compensation imaging modes. Based on the imaging process, the simulator consists of a spatial response module, a spectral response module, and a radiometric response module. The FOV separation is simulated in the imaging position calculation process of the spatial response module, and the motion compensation is considered in both the imaging position simulation and the radiometric response module. Using the simulator, the imaging position data is created to quantify the misregistration. The result shows that the imaging track deviation, caused by the FOV separation, between the VNIR sensor and SWIR sensor keeps a constant quantity in the latitude direction. However, the deviation will increase along with the imaging time in the longitude direction. When the two imaging modes are both considered, the deviation is symmetrical relative to the nadir point in the latitude direction. However, the deviation is not symmetrical in the longitude. In order to analyze the misregistration effect on the imaging data, simulation data with different imaging modes on Dongtianshan remote sensing testing field is created using the simulator. And the misregistration effect on the spectra of flat ground pixel and rugged ground pixel are analyzed.
With the rapid development of China's space industry, digitization and intelligent is the tendency of the future. This report is present a foundation research about guidance system which based on the HSV color space. With the help of these research which will help to design the automatic navigation and parking system for the frock transport car and the infrared lamp homogeneity intelligent test equipment.
The drive mode, steer mode as well as the navigation method was selected. In consideration of the practicability, it was determined to use the front-wheel-steering chassis. The steering mechanism was controlled by the stepping motors, and it is guided by Machine Vision. The optimization and calibration of the steering mechanism was made. A mathematical model was built and the objective functions was constructed for the steering mechanism.
The extraction method of the steering line was studied and the motion controller was designed and optimized. The theory of HSV, RGB color space and analysis of the testing result will be discussed
Using the function library OPENCV on the Linux system to fulfill the camera calibration. Based on the HSV color space to design the guidance algorithm.
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 1.33×10-3Pa 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.