[MetaCRS] A CS-Map usage scenario

[Howard Butler]

On Feb 4, 2009, at 12:31 PM, Norm Olsen wrote:

> Hello Howard . . .
>
> - Does CS-Map read/write/interpret GeoTIFF keys?
> No.  CS-MAP has no knowledge of GeoTIFF keys.

So, along with a GeoTIFF <-> proj4 and GeoTIFF <-> OSR translation  
methods, we need GeoTIFF <-> CS-Map :)

>
>
> - I presume CS-Map does vertical datums.  Is describing those with  
> GeoTIFF keys and WKT a problem?
> CS-MAP does support 3-D operations in a limited way, but not  
> vertical datums explicitly.  In the case of a 3D datum  
> transformation (Molodensky, 7Parameter, Bursa/Wolf, etc) CS-MAP's 3D  
> conversions will use and return the third dimension.  In the case of  
> the NADCON conversion for the 48 states, a 3D conversion will use  
> the VERTCON conversion technique to provide a vertical datum shift.   
> Other than this, there is no explicit support for vertical datums.

I think this will be sufficient. /me hopes the VertCS names and datum  
descriptions from GeoTIFF Just Work (TM).

>
>
> - What would be considered CS-Map's "public API" and how would one  
> going about linking and using CS-Map in your own software?
> I have been working on the documentation (sporadically I admit as we  
> have a code cut-off next week) for the API.  There are two API's  
> which are supported, a High Level Interface and a High Performance  
> Interface.  See attached document for some cut and pastes from the  
> existing documentation which is not quite ready for open source.
>

No document was attached.

> Pardon my ignorance, but with regard to "a convenient way to  
> interact with SRSs", what do you mean by an SRS.
>

Sorry for the imprecise language.  SRS = Spatial Reference System

Howard