[gdal-dev] Re: How to declare State Plane coordinates?

[Paul Selormey]

Hello Frank,
Thanks so much for the support. I think it is all I needed.

Best regards,
Paul.

----- Original Message -----
From: "Frank Warmerdam" <warmerdam at p...>
To: "gdal-dev" <gdal-dev at yahoogroups.com>
Sent: Tuesday, August 21, 2001 10:08 PM
Subject: Re: [gdal-dev] Re: How to declare State Plane coordinates?


> Paul Selormey wrote:
> > Hello All,
> > Is there any function similar to the SetStatePlane to implement the
> > Japanese 19 coordinate systems? Or a guide to implement one?
>
> Paul,
>
> I am not familiar with this zone system; however, looking in the EPSG
> tables I do see a 19 zone japanese system which I presume is the one you
> are referring to. If you have the EPSG support files installed properly
> with GDAL (the data files from gdal/data) you should be able to define
> one of these coordinate systems like this:
>
> OGRSpatialReference oSRS;
>
> oSRS.importFromEPSG( 30160 + nZone );
>
> Alternatively, it looks like you could hand define Zone I something like
this:
>
> OGRSpatialReference oSRS;
>
> oSRS.SetTM( 53.5, -8.0, 1.000035, 200000.0, 250000.0 );
> oSRS.SetGeogCS( "Tokyo", "Tokyo", "Bessel",
> 6377340.189, inverse_flattening );
> oSRS.SetTOWGS84( 506, -122, 611 );
>
> The inverse flattening would have to be computed from the semi-minor axis
> which is 6356034.448. The formula is:
> invserse_flattening = 1/f = 1 / (semimajor/semiminor - 1.0)
>
> I hope this helps.
>
> Best regards,
>
> --
> ---------------------------------------+----------------------------------
----
> I set the clouds in motion - turn up | Frank Warmerdam,
warmerdam at p...
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush | Geospatial Programmer for Rent
>
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