SISTER: DESIS L2B Vegetative Biochemical Traits 30 m V001

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 vegetative biochemical traits (chlorophyll content only) at 30-m spatial resolution derived from data measured by the DLR Earth Sensing Imaging Spectrometer (DESIS) instrument (https://www.dlr.de/eoc/desktopdefault.aspx/tabid-13614). For the purposes of SISTER, only a handful of scenes have been selected from this mission, with a temporal range between 2021-08-20 and 2019-02-04 and a spatial coverage that is global in scale. DESIS samples spectra over the visible and near-infrared wavelength range from 400 to 1000 nm with a unique spectral resolution of 2.5 nm. The raw DESIS data is first processed to L1B orthocorrected calibrated radiance by the German Aerospace Center (DLR) and then ingested into the SISTER platform for further downstream analysis. This collection was derived from corrected surface reflectance and fractional cover datasets using partial least squares regression (PLSR) models. Permuted PLSR models for es+E14timating chlorophyll content, nitrogen concentration, and leaf mass per area were developed using coincident NEON AOP canopy spectra, downsampled to 10 nm, and field data collected by Wang et al. (2020). Biochemical trait estimates were only calculated for pixels with greater than 50% vegetation cover. In addition to mean biochemical trait estimates, per-pixel uncertainties were calculated along with a quality assurance mask which flags pixels with trait estimates outside of the range of data used to build the model. The output products are provided in GeoTIFF format in the following units: chlorophyll content (micrograms/cm2), nitrogen concentration (milligrams/gram), and leaf mass per area (grams/m2). Models for nitrogen and leaf mass per area require infrared wavelengths outside of the spectral range of DESIS.

Science Keywords

Data Use and Citation

Data Files