SHAPE 成形——月船3号上的一台光谱偏振计，用于将地球作为系外行星观测
Shaping SHAPE - A spectro-polarimeter onboard Chandrayaan-3 to observe Earth as an Exoplanet
AI总结：
本文介绍搭载于月船3号推进模块的光谱偏振仪SHAPE的设计、测试与在轨性能，该仪器可观测地球圆面积分光谱偏振特征，为类地系外行星研究提供测试平台与观测基准。
AI中文摘要：
宜居地球光谱偏振仪（SHAPE）是搭载于月船3号任务推进模块（轨道器）上的实验仪器，旨在从月球轨道和高椭圆地球轨道对地球进行圆面积分光谱偏振观测。SHAPE是一款紧凑轻便的光谱偏振仪，包含三个子系统：光电探测器系统（EODS）光学模块、EODS电子模块以及射频源（RFS）。由自主研发的80-135 MHz射频源驱动的声光可调滤波器（AOTF），在1.0-1.7 μm近红外（NIR）波长范围内提供光谱滤波，产生两条具有相互垂直线偏振态的窄带光束。仪器光学模块视场约为2.6°，将两条光束聚焦到铟镓砷（InGaAs）探测器上；通过自主设计的低噪声前端电子模块，实现2-4 nm的光谱分辨率。该仪器还集成了处理和电源电子模块，用于信号处理、探测器偏置及子系统控制。本文呈现该仪器的整体设计、发射前地面测试结果以及在轨运行性能；当前配置使SHAPE能够测量地球在不同相位角下的圆面积分特征，为类地系外行星的表征提供测试平台，并为未来系外行星观测提供基准。
英文摘要：
Spectro-polarimetry of HAbitable Planet Earth (SHAPE) is an experimental instrument onboard the Propulsion Module (Orbiter) of the Chandrayaan-3 mission, designed to perform disc-integrated spectro-polarimetric observations of Earth from lunar and highly elliptical Earth orbits. SHAPE is a compact, lightweight spectro-polarimeter comprising three subsystems: the Electro-Optical Detector System (EODS)-Optics, EODS-Electronics, and Radio Frequency Source (RFS). An Acousto-Optic Tunable Filter (AOTF), driven by an in-house-developed 80$-$135 MHz RF source, provides spectral filtering in the near-infrared (NIR) wavelength range of 1.0$-$1.7 $μ$m and produces two narrow-band beams with mutually perpendicular linear polarization states. The instrument optics, with a field of view of approximately 2.6°, focus the two beams onto InGaAs detectors. A spectral resolution of 2$-$4 nm is achieved using in-house-designed low-noise front-end electronics. The instrument also incorporates processing and power electronics for signal processing, detector biasing, and subsystem control. We present the overall instrument design, results from pre-launch ground-based testing, and in-orbit operational performance. The current configuration enables SHAPE to measure disc-integrated signatures of Earth over a range of phase angles, providing a test bed for characterizing Earth-like exoplanets and benchmarking future exoplanet observations.
