[gdal-dev] Improved support of OziExplorer datums

[Jean-Claude REPETTO]

On 01/07/11 22:48, Frank Warmerdam wrote:
>
> I have two comments:
>
> 1) Please call the files ozi_ellips.csv and ozi_datum.csv

Sorry, it was a typo. Obviously, the names are ozi_ellips.csv and 
ozi_datum.csv.

> 2) What is the origin of these files? What is their licensing? We
> can't just take files from other software packages and release them as
> part of GDAL unless they are under a compatible license, or the copyright
> holder gives us explicit permission to release them under the GDAL license.

I have created both files.

The ellipsoid parameters are standard, and ellipsoid names have exactly 
the same spelling as in the Online-Help page of OziExplorer ("Adding 
User Datums"). But it not necessary, it is just for cosmetic reasons. 
The ellipsoid names could even be removed, but it would be less easy for 
users to add custom datums.

The datums names are exactly the sames as those displayed by OziExplorer 
(Menu : Display, Datum Parameters). This is necessary for the string 
comparisons to succeed when parsing .map files. The datum names have 
been copied manually to the ozi_datum.csv file.
The EPSG numbers are coming from the EPSG database.
The 3-parameters transformation value are those displayed by OziExplorer 
  (Menu : Display, Datum Parameters). They have been copied manually to 
the ozi_datums.csv file. Most of these parameters (and the datum names) 
are the same as in the datum list from the NGA, I think this is where 
the OziExplorer author took them.

Regards,
Jean-Claude