Royer Clément, Poulet F, Reess J-M, Pilorget C, Hamm V, Fouchet T, Maurice S, Forni O, Bernardi P, Montmessin F, Lapauw L, Parisot J, Bonafous M, Gasnault O, Wiens R C
Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, 91405 Orsay, France.
LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, 5 Place Jules Janssen, 92195 Meudon, France.
Rev Sci Instrum. 2020 Jun 1;91(6):063105. doi: 10.1063/1.5145390.
Near-infrared spectroscopy has become a well-known remote sensing technique for the surface characterization of planetary objects. Among them, Mars was observed in the past by three imaging spectrometers from orbit. The Infrared Spectrometer/SuperCam instrument performs near-infrared spectroscopy from the martian surface for the first time, with a 1.15 mrad field of view, in the 1.3 µm-2.6 µm range, enabling the identification of a variety of mafic and altered minerals. Before integration aboard the rover, the spectrometer underwent a calibration campaign. Here, we report the radiometric and linearity responses of the instrument, including the optical and thermal setups used to perform them over its nominal range of operations, in terms of instrument detector temperatures and spectral range. These responses were constrained by accuracy requirements (20% in absolute radiometry, 1% in relative). The derived instrument transfer function fits within these requirements (<15% in absolute and <0.8% in relative) and shall be used to calculate the expected instrumental signal-to-noise ratio for typical observation scenarios of mineral mixtures expected to be found in the Jezero crater, and ultimately to retrieve the spectral properties of the regions of interest observed by the rover.
近红外光谱已成为一种用于行星物体表面特征表征的知名遥感技术。其中，过去曾有三台成像光谱仪从轨道上对火星进行观测。红外光谱仪/超级相机仪器首次在火星表面进行近红外光谱测量，视场为1.15毫弧度，波长范围在1.3微米至2.6微米之间，能够识别多种镁铁质和蚀变矿物。在集成到火星车之前，该光谱仪进行了校准活动。在此，我们报告该仪器的辐射响应和线性响应，包括在仪器探测器温度和光谱范围内，在其标称工作范围内用于执行这些响应的光学和热学设置。这些响应受到精度要求的限制（绝对辐射测量精度为20%，相对精度为1%）。导出的仪器传递函数符合这些要求（绝对精度<15%，相对精度<0.8%），并将用于计算在杰泽罗陨石坑预计会发现的典型矿物混合物观测场景下的预期仪器信噪比，并最终用于反演火星车观测的感兴趣区域的光谱特性。
