Visible-Shortwave Infrared (VSWIR) Spectral Parameters for the Lunar Trailblazer High- resolution Volatiles and Minerals Moon Mapper (HVM3)

The Lunar Trailblazer smallsat mission High-resolution Volatiles and Minerals Moon Mapper (HVM3) science instrument will acquire targeted spectral image cubes of the lunar surface at visible to shortwave infrared (VSWIR) wavelengths (0.6 µm – 3.6 µm) in an effort to understand the distribution, abundance, and form (OH, H2O, ice) of lunar water, as well as the lunar water cycle. Spectral parameters derived from HVM3 VSWIR reflectance spectra, to be used as indicators of mineral and water presence on the lunar surface, will be delivered to the scientific community. Here, we describe the formulation and testing of VSWIR spectral parameters in preparation for returned data from HVM3 using global image cubes and mosaic data from the Moon Mineralogy Mapper (M3) imaging spectrometer, the HVM3 predecessor, and the Deep Impact spacecraft. We expand upon the existing M3 global spectral parameter library, test the efficacy of newly formulated parameters individually and alongside existing M3 spectral parameters, provide examples of quantitative thresholds intended to indicate robust mineral detections, and acknowledge spectral parameter limitations. We demonstrate that newly formulated and existing parameters capture lunar mineral diversity well and serve as a reliable indicator of lunar surface hydration, making them useful for HVM3 scientific analysis.

月球开拓者（Lunar Trailblazer）小卫星任务的高分辨率挥发物与矿物月球测绘仪（High-resolution Volatiles and Minerals Moon Mapper，简称HVM3）科学载荷，将在可见至短波红外（visible to shortwave infrared，简称VSWIR）波段（0.6 µm – 3.6 µm）获取月球表面的定向光谱图像立方体，旨在探明月球水的分布、丰度与赋存形态（羟基OH、水分子H₂O、冰），并研究月球水循环。从HVM3 VSWIR反射光谱中提取的光谱参数，可作为月球表面矿物与水存在的指示因子，相关成果将向国际科学界公开。
本文针对HVM3传回数据的预处理需求，依托其前代仪器——月球矿物测绘仪（Moon Mineralogy Mapper，简称M3）成像光谱仪与深度撞击（Deep Impact）航天器获取的全球光谱图像立方体及镶嵌数据，阐述了VSWIR光谱参数的构建与测试流程。我们在现有M3全球光谱参数库的基础上进行拓展，分别测试了新构建参数与现有M3光谱参数的应用效能，提供了可用于稳健矿物探测的定量阈值示例，并说明了光谱参数的应用局限性。研究证实，新构建与现有光谱参数能够较好地刻画月球矿物多样性，可作为月球表面水合状态的可靠指示因子，适用于HVM3的科学分析工作。