Unambiguous detection of OH and H 2 O on the Moon from Chandrayaan-2 Imaging Infrared Spectrometer reflectance data using 3 μm hydration feature

Imaging Infrared Spectrometer (IIRS) on-board Chandrayaan-2 is designed to measure lunar reflected and emitted solar radiation in 0.8–5.0 μmm spectral range. Its high spatial resolution (~80 m) and extended spectral range is most suitable to completely characterize lunar hydration (2.8–3.5 μmm region) attributed to the presence of OH and/or H₂O. Here we present initial results from IIRS reflectance data analysed to unambiguously detect and quantify lunar 3 μmm absorption feature. After pre-processing and data-reduction, a physics based thermal correction analysis of IIRS reflectance spectra has been done using co-located temperature measurements. Hydration absorption was observed at all latitudes and surface types with varying degrees for all pixels in the study area and its absorption depth shows distinct variability associated with mineralogy, surface temperature and latitude.