Stray light simulation and analysis is one of the key means to ensure high-accuracy polarization radiation data of the directional polarization camera. According to the structural and operating principle of optical system, the dominated resource of the stray light is analyzed. For the difficulty of applying point-source transmittance method to analyze stray light in large field optical system, method for analysis of stray light based on the principle of black spot is presented. Instrumental three-dimensional geometry model and optical property are established by software of LightTools. The influence of stray light inside and outside the field-of-view of optical-mechanical system is simulated respectively by means of selected field point backward tracing. The result shows that the effect of stray light mainly comes from inside the field-of-view, and on-axis field is influenced mostly. The stray light coefficient is 3.27% which satisfies the requirement of design index. In addition, global stray light and local stray light are simulated by on-axis and real ray forward tracing which provides a theoretical basis and guidance for subsequent image stray light correction.

HgCdTe detector was used to detect the interference spectra of CO2 greenhouse gases on spaceborne greenhouse gas detection equipment. The performance of HgCdTe detector is significantly affected by operating temperature, and the detector needs to work at a constant low temperature. According to the operating temperature requirement, a temperature control system for spaceborne HgCdTe detector was designed. The system is mainly composed of temperature acquisition circuit, power-driven circuit and a main control unit based on FPGA. PID algorithm was adopted to realize precise temperature control. The experiment and application results show that the temperature control precision is better than ±0.5℃, and the temperature stability is better than ±0.1℃/s, which satisfies the on-orbit working temperature requirement of HgCdTe detector.

Power-supply is the “energy” of electronics for space payload. The design of the power-supply for an optic remote sensing equipment in GF-5 satellite is analyzed and researched, which includes design of protect circuit, inrush current limiting circuit, switch circuit, filter circuit, reliability design, et al. The results satisfy for the requirements of the relevant standards, and the target is designed on their own characteristics. The identification experiments and acceptance test were passed. The design with high-reliability and high engineering practical value is applied in space detection.

Differential optical absorption spectrometer is a spaceborne optical instrument with precision mechanical structure aboard GF-5 satellite, and there are high temperature stability requirements to the optical-mechanical system and the detector throughout its life cycle. In order to ensure the accuracy of the optical path, the optical installation plate temperature gradient needs to be less than 2℃. In order to reduce the interference of temperature fluctuation to the signal, the temperature fluctuation within whole track is required less than 2℃. Locating with several payloads around, the thermal environment is complex, which makes the design of thermal control difficult. In combination with the thermal control requirements and structural characteristics of the spectrometer, the thermal flow outside on the orbit is analyzed in detail. The side toward earth is used as a heat dissipation surface. The isothermal design is applied for the optical bottom plate. The sunward surface of the instrument is taken as an electronic heat dissipation surface. Some measures are performed to keep the heat insulation between electronic box and optical box. The high stability of temperature control for the spectrometer is realized. The thermal balance test and on-orbit data show that the thermal control design of the spectrometer is reasonable and feasible, and can meet the temperature index demand for on-orbit detection. It builds a good foundation for the high-precision and high-stability thermal control design of the follow-up optical remote sensing instruments.

Spaceborne differential optical absorption spectrometer has three working modes: earth observation, spectrum calibration with solar, and halogen light detector self-inspection with halogen light. Therefore, three corresponding optical systems are needed. To make full use of the optical path, the three optical systems share part of the optical path. So, the solar baffle moving parts, the optical road switching moving parts, and the diffuser plate calibration moving parts are designed to switch the three optical paths. The three moving parts were tested for life, and the whole machine was tested by thermal vacuum and heat balance. The experimental results show that the moving parts are operating normally, and the moving parts meet the life requirements and environmental adaptation requirements.

The coupling is one of the core components of rotatable parts in directional polarization camera, which is responsible for transmitting torque and ensuring the high precision operation of the rotating wheel in the instrument. The characteristics of the instrument require that the coupling has small deformation force, long life and high transmission precision. According to these requirements, a parallel line cutting coupling is designed, and the simulation analysis is carried out. Then the performance of the coupling is designed, including deformation force test, long life test and transmission precision test. Test results show that when the camera is installed within the error range, the deforming force is no more than 10.75 N, which meets the needs of bearing in the camera. After the test of start-running-stop for 40000 times, the driving ability of coupling has no obvious drop, the transmission precision is 4.684×10-5, which meets the requirement of the camera at the end of lifetime, and proves that the coupling meets the life and performance requirements of the camera.

ECRS, the abbreviation for eliminate, combine, rearrange and simplify, is important and widespreadly applied in industrial engineering. Aiming at the present test situation of optical payload on space launch site, the relationship between tasks in test procedure was analyzed based on the results of earlier missions. ECRS analytical method was used for optimizing test procedure, shortening the period of test launch, enhancing the comprehensive test launch capability and ensuring reliability and safety. Finally, the trend in optimization of test procedure on space launch site was predicted.

The problem of China’s atmospheric environmental pollution is grim. Emission source of SO2 and NOx comes from thermal power plants, coal-fired boilers which are based on coal burning. The current standard of coal-fired flue gas emission is strictly defined, so that more stringent requirements of on-line monitoring technology for continuous emission of flue gas are put forward. Based on the method of differential absorption spectroscopy, the analyzer of SO2 and NO pollution gases in coal-fired power plant was studied. According to the absorption spectrum of SO2 and NO, using SiC lamp as the light source, the measurement band of 1900～2600 nm is carried out. By using the least square method, correlation coefficient of two sets of equipment is calculated. As a result, the analyzer can meet the demand of ultra low emission gas monitoring.

Scented highlighter is widely used by primary and secondary students, but it is not certained that whether scented highlighter has toxicity. Therefore the first mass spectrometry analysis for the volatiles from the domestic scented highlighter was carried out. The volatiles emitted from the whole highlighter and each disassembled components were detected using solid-phase microextraction gas chromatography mass spectrometry (SPME-GC-MS). The experimental results showed that the highlighter odor arises from the ink inside. In four brands of mini highlighters, 15 kinds of volatile compounds were detected. Among them, high toxic acrylonitrile and banned additive ethylbenzene occurred in all brands. Using proton transfer reaction mass spectrometry online monitoring method, during highlighter wrote on the paper, the concentrations of acrylonitrile diffused to different height positions above the paper were determined. It is suggested that, as long as the distance from the paper is more than 20 cm, the infringement caused by inhaling poisonous odor can be effectively reduced.

In order to realize the performance test of the spaceborne directional polarization camera (PDC) in the installation stage and environment simulation test, a light source with multi-angle, multi-spectral and polarization features is designed. The final design bases on the principle of the PDC instrument and test requirements is composed of 29 multi-band LED parallel light tubes arranged in a chinese character “mi”-shaped pattern. Through optical modeling, parameters of the parallel light tube diameter, divergence angle and installation field are analyzed. On the basis of radiance calculation analysis, the design of LED driver, diffusion plate, attenuator, polarizer, and depolarizer component was finished, uniform spot illumination and standard polarized light output were realized, the multi-spectral and different dynamic range test of the instrument were satified. The test results show that it meets the multi-field multi-spectral and polarized test requirements, and the stability of source is better than 99.2% within 2 hours, polarization accuracy is better than 1%, reset accuracy is better than 1 pixel. It can meet the requirements of 5% of radiation, 2% of polarization, the performance requirement of geometry 1 pixel, and the monitoring of channel switching function.

Shaanxi Province is the climate sensitive region of China, locating at northwest inland. The probability distribution of water cloud, cloud-top height, optical thickness and the effective radius of cloud are analyzed by using MYD06-L2 of MODIS cloud product to understand the property of water cloud over Shaanxi. The results were concluded as follows: (1) Single peak was obtained for probability distribution pattern of water cloud and reached the top at November, while the lowest at May. Moreover, the maximum and minimum appearance probabilities were observed at autumn and spring. (2) The probability distribution of water cloud-top height produced significant change in July and September, and from April to May, the water could-top height mean value reached the maximum and from December to February the minimum mean value appeared, and specially that of July and August showed distinct form. (3) It was found that the probability distributions of the effective radius of cloud particle are similar from October to May the next year, while obvious differences existed from June to September. The maximum and minimum average appeared from June to August and in November, respectively. (4) The water cloud with optical thickness ranging 0～5, had a higher probability from October to May the next year and reached the top from December to February the next year. Yet, water cloud with optical thickness ranging 5～10 performed different. The higher probability existed from May to October, and reached the top from July to August. Additionally, the maximum and minimum of optical thickness occure from September to November and July to August, respectively.