SISTER: PRISMA L2B Vegetative Biochemical Traits 30 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 vegetative biochemical traits (nitrogen concentration, leaf mass area, and chlorophyll content) at 30-m spatial resolution derived from data measured by the PRecursore IperSpettrale della Missione Applicativa (PRISMA) satellite (https://www.asi.it/en/earth-science/prisma/). For the purposes of SISTER, only a handful of scenes have been selected from this mission, with a temporal range between 2020-02-16 and 2022-05-08 and a spatial coverage that is global in scale. PRISMA measures reflected radiance at better than 12-nanometer (nm) intervals in the visible to shortwave infrared spectral range between 400 and 2500 nm. The raw PRISMA data are first processed to L1B orthocorrected calibrated radiance by the Italian Space Agency (ASI) 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 estimating 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).

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Data Files