[PROJ] (Angular/Linear/Scale) speed in C++ API

[Martin Desruisseaux]

Le 28/11/2019 à 00:19, Even Rouault a écrit :

> Couldn't find in 
> http://docs.opengeospatial.org/is/18-010r7/18-010r7.html an example 
> for a time-dependant operation nor more formal requirements, but 
> https://www.epsg-registry.org/export.htm?wkt=urn:ogc:def:coordinateOperation:EPSG::8070 
> uses those type of nodes for the units of the rate of changes
>
Just for information (not a request for change), Units of Measurements 
in ISO 19111 are defined by ISO 19103:2015 figure C.4. In addition of 
Length, Angle and Scale measures, that standard defines also Speed and 
AngularSpeed (and more). I'm not sure why the EPSG database does not use 
them.

But anyway this email is for another question. In the C++ API, class 
WKTParser provides a guessDialect(string) method. But I do not see a way 
to tell WKTParser::createFromWKT(string) that the given string is known 
to be a GDAL flavor of WKT 1, or the OGC 01-009 standard WKT 1. Both of 
them differ in the interpretation of unit of measurement in PRIMEM and 
PARAMETER elements, and it seems to me hazardous to guess the flavor 
automatically (I realize that it the case of PRIMEM we may rely on the 
prime meridian name, but it is not guaranteed to work and it may not 
solve the PARAMETER case). Did I missed something?

     Thanks

         Martin