Add GSD95 Geoid Model from ca_nrc

OSGeo / PROJ-data

Repository for proj datum grids (for use by PROJ 7 or later)

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Add GSD95 Geoid Model from ca_nrc #108

Open bmckilligan opened 1 year ago

bmckilligan commented 1 year ago

https://webapp.geod.nrcan.gc.ca/geod/data-donnees/geoid.php?locale=en

there are two version nad83(CSRS) and ITRF .byn format

https://webapp.csrs-scrs.nrcan-rncan.gc.ca/geod/process/download-helper.php?file_id=GSD95n83 https://webapp.csrs-scrs.nrcan-rncan.gc.ca/geod/process/download-helper.php?file_id=GSD95

Attached is the ITRF .byn downloaded from nrcan

Additionally, if of use, an exported geotiff created using Qgis.

GSD95.zip NGSD95_tiff.zip

rouault commented 1 year ago

GSD95 is indicated to be superseded, and it is not referenced in the EPSG dataset. IMHO, it would thus be moderately useful for most end users to include it in PROJ-data. Only advanced ones may use it and they could just fetch the TIFF from the NRCan website.

bmckilligan commented 1 year ago

Yes it is deprecated, unfortunately some legacy local coordinate systems use it, the instance I'm looking at is in the petroleum mining sector. They use if for all their survey work, and have it set up in all the Trimble survey equipment. Ironically the parent companies are part of the IOGP