“高分四号”卫星凝视相机具有高时间分辨率、较高空间分辨率和较大成像幅宽的特点。它包含可见光近红外（VNIR）通道和中波红外（MWIR）通道，VNIR通道有5个谱段，MWIR通道有1个谱段，具备昼夜成像能力。相机光学系统为折反射系统，采用分色片实现VNIR与MWIR谱段分离，利用旋转滤光轮将入射VNIR辐射分成5个谱段。VNIR焦面组件采用全局电子快门CMOS面阵探测器；MWIR焦面采用HgCdTe面阵探测器，由脉冲管制冷机制冷到80K。MWIR谱段采用两个黑体进行星上定标。基于用户需求和地球静止轨道环境开展了相机与卫星平台一体化设计、光学系统力学和热学稳定性设计、微振动抑制设计、活动机构长寿命高可靠性设计。%The multispectral staring camera on board GF-4 satellite has the characteristics of high tem-poral resolution, higher spatial resolution and wider coverage. It includes visible and near infrared (VNIR) channel and middle wave infrared (MWIR) channel. The VNIR channel has five spectral bands, while MWIR channel has one spectral band with day and night imaging capability. Its optical system adopts a catadioptric system. A dichroic beam-splitter is utilized to separate VNIR spectral bands from MWIR spectral band, and a filter wheel assembly is used to split the in-coming VNIR radiant flux into 5 spectral bands. The VNIR focal plane assembly uses CMOS area array detector with global shutter, while the MWIR focal plane assembly uses HgCdTe area array detector cooled to 80K by pulse tube cooler. On board calibration of MWIR spectral band is achieved with two blackbodies. Integrated design of the camera and the platform, mechanical and thermal sta-bility design of optical system, micro-vibration suppression design, long-life and high reliability design of me-chanisms are conducted based on user’s requirements and geostationary earth orbit environments.
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