Global Mapper v26.0

Geotiff reprojection from WGS84 to GRS80 ellipsoid shows no curvature

JohnW
JohnW Global Mapper User
in Projection Questions

Looking to take this geotiff...

https://cdn.star.nesdis.noaa.gov/GOES16/ABI/FD/GEOCOLOR/GOES16-ABI-FD-GEOCOLOR-10848x10848.tif

... & make it look like the images shown on the g16 full disk page here:

https://www.star.nesdis.noaa.gov/goes/fulldisk.php?sat=G16

The geotiff loads fine, but when I reproject to GRS80, save .png with .prj data, unload all, then open the .png, I see no curvature on the latitudnal lines.

What's the trick to get this to work?

Answers

  • JohnW
    JohnW Global Mapper User

    Perhaps the better question would be, how to get GM to export a raster in the globe view with curvature of the earth?

    I need the exported projection to display spherically like the images below.

    The thumbnail on our ingest software shows the goes east view as GRS80.

    goes_east_fulldisk_projection_reference.png
    goes_east_fulldisk_thumb.png


  • JohnW
    JohnW Global Mapper User
    Answer ✓

    Got it... reprojected to Orthographic & specified central longitude & latitude for map center. It certainly wasn't GRS80.

  • JohnW
    JohnW Global Mapper User

    Of course... spoke too soon.

    The projection is not orthographic either. Needs to show curvature on both lat & lon grid lines. Tried Azimuthal Equidistant & Gnomonic... still can't get the fulldisk geotiff to rectify & match fulldisk jpeg downloads from star.nesdis site.

    Also tried some G16 netCDF files from here...

    https://home.chpc.utah.edu/~u0553130/Brian_Blaylock/cgi-bin/goes16_download.cgi

    Getting unsupported HDF5 dataset on open data with GM.

    Frustrating. Thanks NOAA... just need an geotiff example matching the projection shown in your image downloads.

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