EMIT L2B Estimated Mineral Identification and Band Depth and Uncertainty

EMIT L2B Estimated Mineral Identification and Band Depth and Uncertainty (EMITL2BMIN V001) is a per-pixel surface mineralogy product derived from the Earth Surface Mineral Dust Source Investigation (EMIT) imaging spectrometer aboard the ISS. It is produced and distributed by NASA JPL and LP DAAC at 60 m ground sample distance across the VNIR-SWIR range (380-2500 nm).^[1][2]

The L2B product applies Tetracorder spectral fitting against the USGS spectral library. Two independent fitting groups run per pixel: one targeting clay-carbonate-sulphate absorptions in the SWIR (approximately 2100-2400 nm), the other targeting iron-oxide absorptions in the VNIR (approximately 700-1000 nm). Each group returns a mineral identification, estimated band depth, and r-squared fit score independently; a pixel may carry confident identifications from one group and low-confidence results from the other.^[2][3] Ten mineral classes are fully validated in the product; additional minerals are identified for transparency but without complete validation.^[1]

illite and muscovite are reported as a combined class because their diagnostic absorptions near 2200 nm overlap at EMIT's 7.4 nm spectral sampling, preventing reliable separation.^[2]

The CMR record lists 285 instrument channels for EMIT.^[4] The L2B ATBD describes 284 science channels after spectral calibration.^[2] Both figures refer to the same instrument; the one-channel difference reflects calibration processing at the science-band boundary.

L2B data are delivered in spatially raw (non-orthocorrected) format; users must apply orthorectification before GIS integration or cross-sensor comparison. ISS orbit constrains coverage to approximately 52 S to 52 N latitude. A significant data gap exists from 13 September 2022 to 6 January 2023 due to ISS external power issues. NASA Earthdata account registration is required for download.^[1][5]