[Gdal-dev] What algorithm employed in ogr2ogr map projection about UTM to Transverse Mercator Projection

[Frank Warmerdam]

Hisaji ONO wrote:
> Hello.
> 
>  UTM and Transverse Mercator Projection has almost same
> projection method.
> 
>  What kind of algorithm are employed in ogr2ogr's map
> projection about conversion from UTM to Transverse
> Mercator Projection in same area?
> 
>  Could it be that UTM-> geographic coordinates ->
> Transverse Mercator?

Hisaji,

UTM is indeed just an alias for Transverse Mercator with
particular parameters.  Going from one projection to another
is indeed accomplished by going first to geographic coordinates.
Note that this is all actually done by PROJ.4.

Best regards,
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