[Proj] Portuguese Modified Grid - Datum 73

[OvV_HN]

Dunno, but doesn't the utm projection uses a couple of preset values for 
lat_0, k_0, x_0, y_0, and a calculated value of lon_0?
The tmerc projection seems more appropriate.

Oscar van Vlijmen


----- Original Message ----- 
From: "Roger Oberholtzer" <roger at opq.se>
To: "PROJ.4 and general Projections Discussions" <proj at lists.maptools.org>
Sent: Tuesday, February 16, 2010 1:35 PM
Subject: Re: [Proj] Portuguese Modified Grid - Datum 73


> On Tue, 2010-02-16 at 13:02 +0100, OvV_HN wrote:
>> A couple of months ago I found the following document with descriptions 
>> of
>> several Portuguese projections.
>> See page 22 for SHG73.
>>
>> Projecções Cartográficas
>> João Matos
>> Departamento de Engenharia Civil e Arquitectura
>> (Versão 2.1) –7 Março 2007
>> <http://websig.civil.ist.utl.pt/jmatos/Modules/StandardToolkit/Documents/ViewDocument.aspx?Mid=744&ItemId=34>
>>
>>
>> Oscar van Vlijmen
>
> Looks like what I have. I translate that into this:
>
> +proj=utm +lat_0=39.66825833333333 +lon_0=-8.133108333333334 +k=1 
> +x_0=180.598 +y_0=86.990 +ellps=intl +units=m +no_defs
>
>
> It is the utm of which I am uncertain.
>