###	MEaSUREs BedMachine Antarctica

###	Data downloaded from https://doi.org/10.5067/POJQI54A45HX on 2026-03-17
    Morlighem, M. (2026). MEaSUREs BedMachine Antarctica. (NSIDC-0756, Version 4). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/POJQI54A45HX

###	Processing steps:

    1.  Download .nc from https://doi.org/10.5067/POJQI54A45HX.
    
    2.  File NSIDC-0756_BedMachineAntarctica_19700101-20191001_V04.1.nc in cwd/input
    
    3.  Run 02_extract_tifs.py from working directory (cwd)
        * Reads BedMachine NetCDF from cwd\input\
        * Extracts subdatasets: dataid, bed, surface, thickness, errbed, firn
        * Applies native EPSG:3031 projection
        * Uses mask subvariable to remove ocean areas from surface, thickness, firn
        * Writes each variable as a cloud-optimised GeoTIFF (COG) with noData = -9999
        * Additionally extracts bed elevation by mask class (ocean, ice-free land, grounded ice, floating ice, lake vostok)
        * Writes masked bed rasters to cwd\output\masked\
        
    4.  Optionally create derivatives for elevation surfaces
        gdaldem hillshade -of COG elev_input.tif hillshade.tif -compute_edges -z 1 -az 315 -alt 45 -co COMPRESS=DEFLATE -co BIGTIFF=IF_SAFER
        gdaldem aspect -of COG elev_input.tif aspect.tif -co COMPRESS=DEFLATE -co BIGTIFF=IF_SAFER	
        gdaldem slope -of COG elev_input.tif slope.tif -co COMPRESS=DEFLATE -co BIGTIFF=IF_SAFER