Owing to the abnormal response of the thermal infrared bands of the visible infrared multi-spectral imager(VIMI)aboard GF-5 satellite it is challenging to guarantee the radiometric calibration accuracy;considering this fact,we conducted a supplementary test of ground radiometric calibration.We obtained that the response sensitivity of the thermal infrared bands to the change of instrument cavity temperature and the focal plane temperature was the main reason for this abnormal phenomenon.Furthermore,we analyzed and summarized the law of output signal changing with instrument cavity temperature and focal plane temperature.An absolute radiation calibration algorithm based on instrument temperature and focal plane temperature revise was proposed.It was successfully applied to laboratory absolute radiation calibration of thermal infrared bands of VIMI.The results show that the uncertainty of calibration is 1.36%.

The Planar Interferometric Imaging System samples the object visibility in the Fourier domain and then digitally reconstructs an image. Firstly, the principle of SPIDER imaging is studied, the principle of AWG is analyzed, and the influence of different bandwidth on the visibility of interference fringes is simulated. The results show that increasing the number of spectral channels of AWG can improve the visibility of interference fringes, effectively increase the spatial frequency coverage and improve the imaging quality.

The Segmented Planar Imaging Detector for Electro-optical Reconnaissance (SPIDER) system is an interferometric imaging system based on photonic integrated circuits. It is one of the effective means to improve the resolution of remote sensing imaging, decrease the difficulty of system processing, and reduce the size, weight and power. The current research status of SPIDER is reported. The basic principle and composition was also studied. An imaging model was established based on partially coherent light theory. The method of interference fringe detection is studied based on balanced four quadrature detectors. The index system of imaging system was also analyzed. Finally, the SPIDER imaging capability was simulated and verified. Based on the results of simulation, the imaging ability of SPIDER can broaden its application in remote sensing reconnaissance, spatial situation awareness and other fields.

A drift angle causes image shift in the vertical scanning direction when a space-borne TDI optomechanical scanner is imaging, which affects the imaging quality of the remote sensing imager. In this paper, the reasons of the drift angle of an optomechanical scanner are analyzed and the drift angle model of an optomechanical scanner is established by vector analysis. Taking a pre-research imager as an example, the results show that the drift angle increases with the decrease of scanning angle and the increase of latitude. The influence of drift angle on MTF and the design guidance on the detector array spacing for the imager are discussed. The drift angle model established in this paper can be widely used in space-borne optomechanical scanners and has reference significance for the overall design of optomechanical scanners.

基于光子集成回路的干涉成像系统体积小、质量轻、功耗小、易于加工测试,且系统分辨率不受单个透镜口径尺寸的限制,是未来发展方向之一.文章首先简述了分块式平面光电侦察成像系统(SPIDER)的基本原理与组成,并对SPIDER的发展状况进行了概述,详细分析了各阶段光子集成回路布局、功能变化;分析与总结了SPIDER的关键技术;最后,对该技术未来发展趋势、应用前景进行了分析和讨论.分析表明:SPIDER正朝着基线更长、大规模低功耗高集成度、宽谱段成像方向发展,应用前景广泛.

In satellite imaging with CCD camera, there is a drift angle between earth self-rotating. Be-cause the drift angle can bring crosswise image motion speed which cause the image motion, it is necessary to analyze the influence on image quality. In this paper, an imaging mode of the Three Non-collinear CCD chips is proposed. According to the mechanism and calculation approach of the drift angle, the effect of the drift angle on three non-collinear CCD chips is analyzed. Companying with an example of sun-synchronous orbit, the range of drift angle is controlled to reach the image registration accuracy. When the drift angle is out of control, the horizontal displacement is calculated and the minimal distance between different CCD chips is given.