塑造 SHAPE——搭载于月船号（Chandrayaan-3）上用于观测地球作为系外行星（exoplanet）的谱偏振仪

SHAPE 是一台搭载于月船号（Chandrayaan-3）推进舱上的实验性仪器，旨在从月球和高椭圆地球轨道（earth orbit）对地球进行盘面积分谱偏振观测。该仪器通过近红外（near-infrared）波段的线偏振（linear polarization）测量，为表征地球型系外行星（Earth-like exoplanet）提供了测试平台。

arXiv:2608.19371v1 Announce Type: new Abstract: 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 $\mu$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{\deg}, 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.