Changes between Version 3 and Version 4 of VerticalCS

Timestamp:

Feb 7, 2011, 10:58:21 AM (13 years ago)

Author:

warmerdam

Comment:

--

VerticalCS

@@ -44 +44 @@
 == Ellipsoidal Heights ==
 
-One way of describing elevations is relative to an ellipsoid rather than to a more specialized vertical datum.  The 1.0 GeoTIFF specification ( [http://www.remotesensing.org/geotiff/spec/geotiff6.html#6.3.4.1 section 6.3.4.1) listed ellipsoidal VertCS values in the range 5000 to 5033; however, those do not appear to have any corresponding definitions in modern EPSG databases.  I am currently taking the position that it those should therefore be disregarded.
+One way of describing elevations is relative to an ellipsoid rather than to a more specialized vertical datum.  The 1.0 GeoTIFF specification ( [http://www.remotesensing.org/geotiff/spec/geotiff6.html#6.3.4.1 section 6.3.4.1]) listed ellipsoidal VertCS values in the range 5000 to 5033; however, those do not appear to have any corresponding definitions in modern EPSG databases.  I am currently taking the position that it those should therefore be disregarded.
 
 Instead I propose that we just treat ellipsoidal heights by not specifying any VerticalCSTypeGeoKey code and letting the ellipsoid be determined from the ProjectedCSTypeGeoKey, !GeographicTypeGeoKey or !GeogEllipsoidGeoKey.   Thus a GeoTIFF defined as follows would be assumed to have ellevations in meters relative to the WGS84 ellipsoid.