UM Geospatial Digital Special Collections

Citation: Level-1 and Atmosphere Archive & Distribution System Distributed Active Archive Center (LAADS DAAC), NASA (2024). 2023 Eastern Gulf of Mexico VIIRS Nighttime Lights [gis dataset]. LAADS/NASA. https://doi.org/10.5067/VIIRS/VNP46A4.001. last updated: 2024-11-08 (update frequency: Never). Abstract: VNP46A4 - VIIRS/NPP Lunar BRDF-Adjusted Nighttime Lights Yearly L3 Global 15 arc second Linear Lat Lon Grid The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) supports a Day-Night Band (DNB) sensor that provides global daily measurements of nocturnal visible and near-infrared (NIR) light that are suitable for Earth system science and applications. The VIIRS DNB's ultra-sensitivity in lowlight conditions enable us to generate a new set of science-quality nighttime products that manifest substantial improvements in sensor resolution and calibration when compared to the previous era of Defense Meteorological Satellite Program/Operational Linescan System's (DMSP/OLS) nighttime lights image products. Such improvements allow the VIIRS DNB products to better monitor both the magnitude and signature of nighttime phenomena, and anthropogenic sources of light emissions. VNP46A4 is the short-name for the fourth nighttime lights (NTL) product in the Black Marble suite, which provides yearly composites generated from daily atmospherically- and lunar-BRDF-corrected NTL radiance to remove the influence of extraneous artifacts and biases. Known by its long-name, VIIRS/NPP Lunar BRDF-Adjusted Nighttime Lights Yearly L3 Global 15 arc-second Linear Lat Lon Grid, this product contains 28 layers. They provide information on the NTL composite, the number of observations, quality, and standard deviation for multi-view zenith angle categories (near-nadir, off-nadir, and all angles), their snow-covered and snow-free statuses besides land-water mask, latitude and longitude coordinate information. They also include detailed information and description of the quality flags. This SNPP VIIRS collection-1 product record, identified by its version-ID 001 in its file name, starts from January 1st 2012. Key words: Eastern Gulf Coast, Nighttime lights Open Geospatial Consortium Standards: | WMS (coming soon) | WFS (coming soon) Analytical Functions: gdsc_zonal_statistics(table=egom_2023_viirs_vnp46a4,lat=25.718,lng=-80.279,radius=500) ETL documentation

ETL for egom_2023_viirs_vnp46a4

######### # GDSC ETL is performed in two steps: shell script to ETL data into postgres # and then additional transformations with SQL in postGIS (if needed). #### ######### # Step 1 - bash script (pseudo code) #### # create directory structure and move into it mkdir -p /data/egom_2023_viirs_vnp46a4/{download,etl} && cd /data/egom_2023_viirs_vnp46a4 # set update flag based on last update and update frequency do_update=0 if date() < last_update + update_frequency else do_update = 1 # load raster into postGIS with: raster2pgsql -s 4326 -d -C -I VNP46A4.A2023001.h09v06.001.2024020041202.tif -F -t 256x256 egom_2023_viirs_vnp46a4 > load_raster.sql psql < load_raster.sql rm load_raster.sql # extract subdataset from hd5 and save as tif cd download gdalinfo HDF5:"VNP46A4.A2023001.h09v06.001.2024020041202.h5"://HDFEOS/GRIDS/VIIRS_Grid_DNB_2d/Data_Fields/NearNadir_Composite_Snow_Free | grep BoundingCoord > bounds.txt gdal_translate -a_srs EPSG:4326 -a_ullr $(cat bounds.txt | grep West | cut -d = -f 2) $(cat bounds.txt | grep North | cut -d = -f 2) $(cat bounds.txt | grep East | cut -d = -f 2) $(cat bounds.txt | grep South | cut -d = -f 2) HDF5:"VNP46A4.A2023001.h09v06.001.2024020041202.h5"://HDFEOS/GRIDS/VIIRS_Grid_DNB_2d/Data_Fields/NearNadir_Composite_Snow_Free VNP46A4.A2023001.h09v06.001.2024020041202.tif rm bounds.txt cd .. ######### # Step 2 - SQL script (pseudo code): ####