[CF-metadata] proposed UTM projection

[John Caron]

Rich Signell wrote:

> John & Co.,
>
> Why do we need a new projection for UTM?
>
> UTM is just one type of Transverse Mercator that is completely 
> specified by the map parameters we already have, right?
>
> From the "Grid Mappings" section of CF 1.0:
>
> grid_mapping_name = transverse_mercator
>
> Map parameters:
>
>     * scale_factor_at_central_meridian
>     * longitude_of_central_meridian
>     * latitude_of_projection_origin
>     * false_easting
>     * false_northing
>
>
> So people using UTM just specify the appropriate Transvere Mercator 
> map parameters for their zone, don't they?
>
>
> -Rich
>
Theres 2 parts:

1) Transverse Mercator doesnt specify the ellipsoidal parameters, 
presuming i suppose a spherical earth. Im working with a dataset where 
im told the ellipsoidal form is needed for accuracy..

2) The UTM zone specification is in wide use, and is a shorthand for all 
the other TM parameters.