Finalized optical design of the Surface Biology and Geology (SBG) Visible to Short Wavelength Infrared (VSWIR) Wide Swath Imaging Spectrometer

The Surface Biology and Geology (SBG) Visible to Short Wavelength (VSWIR) Wide Swath Imaging Spectrometer will address the large range of science applications called out in the 2017-2027 Earth Science and Applications from Space Decadal Survey such as coupling of the water to energy cycles, ecosystem change, reducing climate uncertainty and informing societal response, surface dynamics, and geological hazards. The instrument achieves Landsat-like swath of 180km with ground sampling distance of 30m with the use of two identical optical systems are mounted side-by-side with each system covering their respective halves of the field of view. Each spectrometer features a freeform three-mirror anastigmat telescope to feed an optically fast, F/1.8, and highly uniform Dyson Spectral Imager (DSI) with 10nm spectral sampling over a spectral range of 380-2500nm. An overview of the finalized optical design prescription is presented, and the status of the instrument development is discussed.

地表生物与地质（Surface Biology and Geology, SBG）可见光至短波红外（Visible to Short Wavelength, VSWIR）宽幅成像光谱仪，可覆盖《2017-2027年空间地球科学与应用十年调查》中列出的多类科学应用场景，涵盖水-能量循环耦合、生态系统变化、降低气候不确定性并为社会响应提供支撑、地表动态变化以及地质灾害研究等方向。该仪器通过两套完全相同的光学系统并排安装，每套系统分别覆盖各自的半视场，可实现与陆地卫星（Landsat）相当的180千米幅宽及30米的地面采样距离。每台光谱仪搭载自由曲面三反射消像散望远镜，将光线导入光学相对孔径为F/1.8、光学性能高度均匀的戴森光谱成像仪（Dyson Spectral Imager, DSI），该成像仪在380~2500纳米的光谱范围内可实现10纳米的光谱采样间隔。本文对最终确定的光学设计方案进行了概述，并讨论了该仪器的研发进展。