Paul Childs

The TOWGS84 string is a hack to provide conversions between datums. It is left off most Wkt lists because it forces modern GIS libraries to use an inaccurate method of...

double[] eastingNorthingAlt = {411686,4194530,23}; double[] longitudeLatitude = transformer.MathTransform.Transform(eastingNorthingAlt); Also your question should be marked WGS84, not 94

Well Proj4 was updated to support this https://github.com/OSGeo/PROJ/issues/394 Would have to merge in these underlying changes, but if so may as well go the whole hog and target Proj 6+...

Because of the TOWGS84 string the transformation between the spheroids goes via cartesian 3D geocentric coordinates. When transforming back to WGS84 you will end up with an altitude value as...

One thing to note is that in this version TOWGS84 is deprecated. TOWGS84 is currently the only workaround I am aware of in ProjNET for performing datum transformations that libraries...

The SRTM dataset uses EGM96 as listed in the GDAL metadata field in the geotiff files. Mapzen geotiffs have a GDALMetadata field but no information on the vertical coordinate system...

This should have been checked before merging. #1620 has presented a regression. @shadows-withal could you please reopen this issue.