Naming convention of ASTER DEM and NASADEM DEM maps

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m_stricker
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Naming convention of ASTER DEM and NASADEM DEM maps

by m_stricker » Fri Nov 19, 2021 6:25 am America/New_York

Hello,
I just started exploring DEM maps, namely the "ASTER Global Digital Elevation Model V003" and "NASADEM Merged DEM Global 1 arc second V001".
When I use the Earthdata explorer to filter tiles based on their granule IDs (e.g. *N03E008*) I can see that the resulting file is referencing the same location in the ASTER dataset and the NASADEM dataset.
However when reading the official documentations of ASTER ( https://lpdaac.usgs.gov/documents/434/A ... 1635149182 ) and NASADEM ( https://lpdaac.usgs.gov/documents/592/N ... 1635149182 ) they mention, that the naming convention of ASTER refers the latitude and longitude of the southwest corner pixel, while the NASADEM mentions that the name refers the northwest geographic coordinate of tile.
So if I understood the documentation correctly the tiles referring to the same granule ID should cover different locations, which contradicts the visualization of the Earthdata explorer? Or has there been some renaming applied to the files to be consistent throughout different datasets that didn't make it to the official documentation? Can someone please help me clarify that issue?

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LP DAAC - jwilson
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Re: Naming convention of ASTER DEM and NASADEM DEM maps

by LP DAAC - jwilson » Tue Nov 30, 2021 7:37 am America/New_York

Our Subject Matter Expert is currently looking at the User Guides to confirm if they are correct in their explanation of file name relative to the actual tiles. For the NASADEM, if there is anything wrong with the user guide descriptions we have sent the Principal Investigator: Sean Buckley, Jet Propulsion Laboratory to make any modifications.
https://lpdaac.usgs.gov/product_search/ ... &view=list
Thank you,
Janice

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Re: Naming convention of ASTER DEM and NASADEM DEM maps

by LP DAAC - jwilson » Tue Dec 07, 2021 11:54 am America/New_York

The NASADEM DEM tile filenaming convention is the same as the previous SRTM DEM tiles: it corresponds to the southwest corner of the tile. So there must be a typo in the documentation. We will correct the documentation.
Thank you for bringing this to our attention.
Kind regards,
Janice

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