Add support of modern coordinate systems that includes height

[pastaav]

We would like to start using ProjNet4GeoAPI but Proj4NetGeoAPI does not support height information in a good way.

In particular there is no implementation for VERT_CS or for that matter COMPD_CS. When we load a typical swedish coordinate systemem we get the following exception
System.NotSupportedException : COMPD_CS["SWEREF99 18 00 + RH2000 height", PROJCS["SWEREF99 18 00", GEOGCS["SWEREF99", DATUM["SWEREF99", SPHEROID["GRS 1980",6378137,298.257222101, AUTHORITY["EPSG","7019"]], TOWGS84[0,0,0,0,0,0,0], AUTHORITY["EPSG","6619"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4619"]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",18], PARAMETER["scale_factor",1], PARAMETER["false_easting",150000], PARAMETER["false_northing",0], UNIT["metre",1, AUTHORITY["EPSG","9001"]], AUTHORITY["EPSG","3011"]], VERT_CS["RH2000 height", VERT_DATUM["Rikets hojdsystem 2000",2005, AUTHORITY["EPSG","5208"]], UNIT["metre",1, AUTHORITY["EPSG","9001"]], AXIS["Up",UP], AUTHORITY["EPSG","5613"]], AUTHORITY["EPSG","5850"]] coordinate system is not supported. at ProjNet.IO.CoordinateSystems.CoordinateSystemWktReader.ReadCoordinateSystem(String coordinateSystem, WktStreamTokenizer tokenizer)

Not being able to use the same coordinate system as the database and other GIS-software is of course a deal breaker for us and many other companies.

Is there any workaround for the current version of ProjNet4GeoAPI that you can suggest?
Could you provide us with a of roadmap of when a version of ProjNet4GeoAPI can be made available that has the upsteam functionality merged? What kind of effort would be needed to get this done?

[FObermaier]

Is https://github.com/AmpScm/SharpProj an option?

[pastaav]

I suspect SharpProj is .Net (Core) only since there is no informations about supported platforms. This would imply quite an effort for us if the rest of the application need to be rewritten for Core. Currently we are using a x86-only library for coordinate conversions but would need to run x64 for dealing with peak load. We hope to find a solution that allows us to stay on .Net Framework until we are ready to update the rest of the application.

[FObermaier]

It is both. Minimum .Net Framework v4.5.
see: https://www.nuget.org/packages/SharpProj.Core/ (tab Frameworks)

[pastaav]

I undestand...SharpProj.Core lists platforms while SharpProj itself does not have any such information. I will investigate if SharpProj can work in our context.