SISTER: EMIT L2B Aquatic Pigments 60 m V002

Overview

Description

Generated by the Space-based Imaging Spectroscopy and Thermal pathfindER (SISTER) activity in support of the NASA Earth System Observatory's Surface Biology and Geology (SBG) mission, this dataset utilizes existing airborne and spaceborne sources to generate prototype data products spanning terrestrial ecosystems, inland and coastal aquatic ecosystems, hydrology, and geology. The objective of SISTER is to mature many of the workflows, algorithms, and data products envisioned for SBG, lay the groundwork to develop a robust cal/val network, and build a vigorous and expansive user community ahead of launch. This dataset contains experimental Level 2B aquatic pigments (chlorophyll A and phycocyanin concentrations) at 60-m spatial resolution derived from data measured by NASA's Earth Surface Mineral Dust Source Investigation (EMIT) instrument. For the purposes of SISTER, only a handful of scenes have been selected from this mission, with a temporal range between 2022-08-10 and 2023-03-25 and a spatial coverage that is global in scale. EMIT measures reflected radiance at ~7.5 nanometer (nm) intervals in the visible to shortwave infrared spectral range between 381 and 2493 nm. The raw EMIT data are first processed to L1B calibrated radiance by the Imaging Spectroscopy Group at Jet Propulsion Laboratory (JPL) and then ingested into the SISTER platform for further downstream analysis. This collection was derived from corrected surface reflectance and fractional cover datasets using pre-trained mixture density networks (MDN). MDN weights were derived from Pahlevan et al. (2021) for chlorophyll and O'Shea et al. (2021) for phycocyanin. Prior to model application, reflectance datasets were resampled to model wavelengths and pigment concentrations were only estimated on pixels with water fractional cover of greater than 0.9. The output products are provided in GeoTIFF format in units of mg m-3.

Science Keywords

Data Use and Citation

Data Files