Abstract:Earth radiation budget is of significance to the study of weather and climate and their correlation. The spaceborne earth radiation detection technologies in the world are overviewed and the features of geostationary earth radiation budget detection are discussed according to an earth radiation budget detection project.

Abstract:To compensate the defocusing of a dual-band aerial camera in a complicated environment, a focusing mechanism is designed. The mechanism compensates the defocusing by using a worm-gear and an eccentric cam to convert the rotation of the focusing cam into the straight line motion of a mirror. It has the advantages of high transmission ratio, stable operation, compact structure, antivibration, self-locking and modularization. The calculation result shows that its focusing mirror has a displacement precision of 0.0026mm and the simulation result shows that the method is feasible.

Abstract:Through the modification of film fabrication processes, vanadiaum oxide (VOx) films were fabricated on glass and monocrystal silicon substrates by using a DC magnetron sputtering equipment with high-purity oxygen and arg. Then, the VOx films were annealed and their structures and electric properties were detected by using a LCR meter and a X-ray diffraction instrument. The results showed that the TCR of the VOx film on the glass substrate exceeded -0.02/℃ when the gas pressure of 1.5Pa, the power of 100W, the sputtering time of 1 hour and the ratio of oxygen to argon of 0.8∶25 were used after they were annealed at 450℃. By comparing the VOx film on the glass substrate with that on the monocrystal substrate, it was found that the VO$_x$ film on the monocrystal substrate had better quality and properties.

Abstract:Pb1-xGexTe films were deposited on Si substrates via thermal evaporation in vacuum. The influence of the surface status (roughness, temperature, crystal orientation) of the substrates on the infrared optical characteristics of the films was analyzed. It was found that denser layers with higher refraction index were easy gained on smooth substrate surfaces. With the increase of the deposition temperature, the short wave absorption edge (λc) of the film would shift toward longer wavelengths.

Abstract:Highly hermetical laser sealing is a packaging technology which can be used for metal packages. It can achieve the sealing of a small hole of the metal package containing an infrared detector in a high vacuum environment. Thus, both the exhaust process and the sealing process of the infrared detector assembly can be finished at the same time. According to the structure and material of a micro package, the relation of the current and pulse width of a laser welding equipment to welding energy and the influence of the current, pulse width and defocusing distance on welding quality are analyzed. Proper laser welding parameters are obtained for Kovar materials. With those parameters, the laser sealing of a hole of the metal package containing an infrared detector is achieved. The test result shows that its leak rate is better than 1×10-10Torr.l/S.

Abstract:Through the complete analysis of a radiometric calibration process, the uncertainty trasfer relationship between absolute calibration and relative calibration is revealed. In the analysis, the multi-point radiometric calibration method is used for the relative calibration and the standard lamp---diffusion board---integrating sphere routine is used for the absolute calibration. By taking this radiometric calibration chain as a model, the uncertainty equations in the radiometric calibration chain are given and the uncertainty factors due to the relative calibration in these equations are analyzed. Finally, the uncertainty values which can be achieved with the current equipment are calculated. These values are helpful theoretically to the determination of the precision requirement for lab radiometric calibration.

Abstract:The quality of the images obtained by the CCD sensor onboard HJ--1 satellite is evaluated and analyzed in two aspects of image project quality and image application quality. By comparing the result with that of the same temporal Landsat TM image, the quality of the images from the CCD sensor onboard HJ--1 satellite is evaluated objectively. The image project quality evaluation is carried out in three aspects of statistical feature, texture feature and energy feature. The result shows that HJ-1 CCD images can exhibit the shapes, details and textures of objects. The image application quality evaluation is carried out by using HJ-1 CCD images to extract the urban vegetation information in Beijing. The result shows that its information extraction accuracy is better and its total classification accuracy is up to 84.45% which is suitable for the extraction of unban vegetation information.

Abstract:As a all-weather high-tech means being able to monitor the temporal and spacial variation of disasters in a large area dynamically, satellite remote sensing are widely used in disaster monitoring and environmental protection in the world. However, the practical remote sensing data products are rarely available in China. Therefore, how to make remote sensing data products quickly is critical to the wide application of remote sensing data in China. A method for processing multi-temporal remote sensing data quickly and automatically is proposed. Because the Batch Commands in ERDAS are used to process the NDVI data in batches in the method, much manpower and time can be saved. The method is also helpful to the batch processing of similar remote sensing images.