Support for arbitrary GeoTIFF projection parameters #3
Description
This can/should be done first in pure-Python so that we can validate against GDAL/rasterio more easily.
For example, this file:
has these geokeys:
GTModelTypeGeoKey: 1
GTRasterTypeGeoKey: 1
GTCitationGeoKey: "unnamed"
GeographicTypeGeoKey: 4267
GeogCitationGeoKey: "NAD27"
GeogAngularUnitsGeoKey: 9102
GeogSemiMajorAxisGeoKey: 6378206.4
GeogInvFlatteningGeoKey: 294.9786982139006
ProjectedCSTypeGeoKey: 32767
ProjectionGeoKey: 32767
ProjCoordTransGeoKey: 22
ProjLinearUnitsGeoKey: 9001
ProjNatOriginLongGeoKey: -119.75
ProjNatOriginLatGeoKey: 0
ProjFalseEastingGeoKey: 0
ProjFalseNorthingGeoKey: 0
ProjScaleAtNatOriginGeoKey: 1
and gets converted by GDAL into this WKT string:
PROJCRS["unnamed",
BASEGEOGCRS["NAD27",
DATUM["North American Datum 1927",
ELLIPSOID["Clarke 1866",6378206.4,294.978698213898,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4267]],
CONVERSION["American Polyconic",
METHOD["American Polyconic",
ID["EPSG",9818]],
PARAMETER["Latitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",-119.75,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["False easting",0,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",0,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["easting",east,
ORDER[1],
LENGTHUNIT["metre",1,
ID["EPSG",9001]]],
AXIS["northing",north,
ORDER[2],
LENGTHUNIT["metre",1,
ID["EPSG",9001]]]]
Chatgpt seemed to have some useful context:
https://chatgpt.com/share/6938b20a-83fc-8008-a0c9-b03165660a9e