Mantis: an all-sky visible-to-near-infrared hyper-angular spectropolarimeter.

In this paper, we introduce and present first results from Mantis, a pushbroom type spectropolarimeter recently acquired by the Naval Research Laboratory and built by Polaris Sensor Technologies, Inc. The instrument is designed for high spatial and spectral resolution polarimetric imaging of downwelling skylight. Linear Stokes vectors are acquired over the spectral range of 382-1017 nm, with ≈0.64nm channel spacing, and each line scan consists of 2226 pixels over a 72° field of view (0.75 mrad instantaneous). Measurement of the full sky dome is achieved through the use of a high-precision motorized pan-tilt unit and systematic scanning. An automated Sun shade allows for data collection in the main solar plane without saturation of the focal plane. The uncertainty in the degree of linear polarization varies between 0.07% and 0.5%, depending on incidence angle and wavelength. The total radiometric uncertainty is 2.07% to 2.5%, of which 2% is absolute calibration error. Preliminary data analysis reveals the instrument has a large potential for remote sensing applications.

在本文中，我们介绍并展示了Mantis的初步成果。Mantis是一种推扫式光谱偏振计，最近由美国海军研究实验室购置，由北极星传感器技术公司制造。该仪器专为对下行天空光进行高空间和光谱分辨率的偏振成像而设计。它可在382 - 1017纳米的光谱范围内获取线性斯托克斯矢量，通道间距约为0.64纳米，每次线扫描在72°视场（瞬时为0.75毫弧度）内包含2226个像素。通过使用高精度电动云台和系统扫描来实现对整个天空穹顶的测量。一个自动遮阳装置允许在太阳主平面内收集数据，而不会使焦平面饱和。线性偏振度的不确定度在0.07%到0.5%之间变化，这取决于入射角和波长。总辐射不确定度为2.07%到2.5%，其中2%是绝对校准误差。初步数据分析表明，该仪器在遥感应用方面具有很大潜力。