Design And Realization Of Electronic System Of Multi-channel Self-calibration Thermal Infrared Radiometer

Due to the more and more extensive application of thermal infrared remote sensing technology,many countries have launched satellites carrying thermal infrared sensors.Meanwhile,the in-orbit radiation calibration technology of thermal infrared channels matching satellite loads also needs to be improved.At present,the field radiometric calibration experiments of space-borne remote sensors are mostly completed by means of manual running field.In order to further improve the frequency and accuracy of site calibration experiment and reduce the cost of calibration experiment.Developed with functions of long-term automation field observation of multi-channel calibration from Thermal Infrared Radiometer(Multi-channel Self-calibrated Thermal Infrared Radiometer,MSIR),through under the action of computer intelligent control system,the instrument automatically target signal data acquisition,storage and transmission process,is helpful to realize field automation calibration of space-borne remote sensors.According to the application of computer control technology in the development of automatic observation instrument,the design of MSIR electronics system based on STM32 single-chip microcomputer is carried out in this paper,centering on the design requirements and working principles of MSIR and using the traditional embedded control system.The working band range of the instrument is 8?14 ?m.The filter wheel is controlled by a single chip microcomputer to achieve the function of multi-channel observation,which can match more spectral channels of the space-borne infrared remote sensor and improve the measurement accuracy and the applicability of the instrument.By controlling the precise rotation of the reflector with a single chip microcomputer,the target radiance and the downward atmospheric radiation can be measured from multiple angles,which can remove the influence of downward atmospheric radiation on the measurement accuracy of the target.Two built-in black bodies in the instrument are used for real-time self-calibration of the detector response coefficient.The single-chip microcomputer controls the temperature of the black body by closed-loop feedback,which achieves better temperature control stability and improves the calibration precision of the black body to the detector.In order to improve the environmental adaptability of the instrument and avoid the pollution of the internal measuring system by rainwater,a rain-sensing device based on LM555 timer was designed to realize the intelligent self-protection function of the instrument under the control of single chip microcomputer and protection device.At the same time,the utility system and the solar cell system are designed to supply power to the instrument to ensure a stable power supply.Through the design of BD short message communication module,the function of remote wireless transmission of measurement data is realized,and a storage module is added to realize the function of data backup.The automatic and intelligent observation functions of the instrument are realized through the design of the electronic system and the writing of the control software.After the completion of MSIR electronic system design,it is verified through experimental tests that the switching function of multi-channel and multi-angle of the instrument is normal,the built-in black body temperature control function is normal,and the automatic observation function and environmental adaptability are normal.By means of radiation calibration and test of the instrument on the optical platform of the laboratory with the help of non-point source black body,the inherent parameters and calibration coefficients of each channel of the instrument were obtained.After comprehensive consideration of various factors causing the uncertainty of the system,the analysis results showed that the precision of the instrument was±0.2K,meeting the requirements of the design index of the electronic system.