EMIT L2A Estimated Surface Reflectance and Uncertainty and Masks 60 m V001

Description

The Earth Surface Mineral Dust Source Investigation (EMIT) instrument measures surface mineralogy, targeting the Earth’s arid dust source regions. EMIT is installed on the International Space Station (ISS) and uses imaging spectroscopy to take mineralogical measurements of sunlit regions of interest between 52° N latitude and 52° S latitude. An interactive map showing the regions being investigated, current and forecasted data coverage, and additional data resources can be found on the VSWIR Imaging Spectroscopy Interface for Open Science (VISIONS) EMIT Open Data Portal. The EMIT Level 2A Estimated Surface Reflectance and Uncertainty and Masks (EMITL2ARFL) Version 1 data product provides surface reflectance data in a spatially raw, non-orthocorrected format. Each EMITL2ARFL granule consists of three Network Common Data Format 4 (NetCDF4) files at a spatial resolution of 60 meters (m): Reflectance (EMIT_L2A_RFL), Reflectance Uncertainty (EMIT_L2A_RFLUNCERT), and Reflectance Mask (EMIT_L2A_MASK). The Reflectance file contains surface reflectance maps of 285 bands with a spectral range of 381-2493 nanometers (nm) at a spectral resolution of ~7.5 nm, which are held within a single science dataset layer (SDS). The Reflectance Uncertainty file contains uncertainty estimates about the reflectance captured as per-pixel, per-band, posterior standard deviations. The Reflectance Mask file contains six binary flag bands and two data bands. The binary flag bands identify the presence of features including clouds, water, and spacecraft which indicate if a pixel should be excluded from analysis. The data bands contain estimates of aerosol optical depth (AOD) and water vapor. Each NetCDF4 file holds a location group containing a geometric lookup table (GLT) which is an orthorectified image that provides relative x and y reference locations from the raw scene to allow for projection of the data. Along with the GLT layers, the files will also contain latitude, longitude, and elevation layers. The latitude and longitude coordinates are presented using the World Geodetic System (WGS84) ellipsoid. The elevation data was obtained from Shuttle Radar Topography Mission v3 (SRTM v3) data and resampled to EMIT’s spatial resolution. Each granule is approximately 75 kilometer (km) by 75 km, nominal at the equator, and some granules near the end of an orbit segment reaching 150 km in length.

Resources

Name Format Description Link
33 The Algorithm Theoretical Basis Document (ATBD) describes the physical and mathematical algorithms for the product. https://lpdaac.usgs.gov/documents/1571/EMITL2A_ATBD_v1.pdf
21 Search results for publications that cite this dataset by its DOI. https://scholar.google.com/scholar?q=10.5067%2FEMIT%2FEMITL2ARFL.001
21 The EMIT website provides detailed information on the mission, instrument, products, etc. https://earth.jpl.nasa.gov/emit/
21 The LP DAAC product page provides information on Science Data Set layers and links for user guides, ATBDs, data access, tools, customer support, etc. https://doi.org/10.5067/EMIT/EMITL2ARFL.001
33 The technical information in the User's Guide enables users to interpret and use the data products. https://lpdaac.usgs.gov/documents/1569/EMITL2ARFL_User_Guide_v1.pdf
21 EMIT Level 2A science data system repository. https://github.com/emit-sds/emit-sds-l2a
32 Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. https://search.earthdata.nasa.gov/search/granules?p=C2408750690-LPCLOUD
21 Watch the EMIT Data Tutorial Series Workshops to learn how to discover, access, and work with EMIT datasets. https://www.youtube.com/playlist?list=PLO2yB4LGNlWrC5NdxeHMxyAxdwQhSypXe
21 The LP DAAC GitHub repository provides guides, Python notebooks, and scripts to help users access and work with data from the EMIT mission. https://github.com/nasa/EMIT-Data-Resources
21 EMIT data E-Learning resources provided by NASA's LP DAAC. https://lpdaac.usgs.gov/search/?query=EMIT&content_types=E-Learning&view=cards&sort=relevance
34 Browse image for Earthdata Search. https://data.lpdaac.earthdatacloud.nasa.gov/lp-prod-public/EMITL2ARFL.001/EMIT_L2A_RFL_001_20240705T004833_2418616_021/EMIT_L2A_RFL_001_20240705T004833_2418616_021.png
21 Python Tutorial: Exploring EMIT L2A Reflectance shows how to open an L2A reflectance NetCDF file, inspect the structure, plot the data spatially, and examine spectra at a specific location. https://git.earthdata.nasa.gov/projects/LPDUR/repos/emit_tutorials/browse/01_Exploring_L2A_Reflectance
21 The LP DAAC website provides detailed information on discovery, distribution, access, and support of land data products. https://lpdaac.usgs.gov/
21 The Application for Extracting and Exploring Analysis Ready Samples (AρρEEARS) offers a simple and efficient way to perform data access and transformation processes. https://appeears.earthdatacloud.nasa.gov/

Tags

  • infrared-wavelengths
  • visible-wavelengths
  • sensor-characteristics
  • spectral-engineering
  • platform-characteristics
  • earth-science

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