EPSG code for...

[Dean Mikkelsen]

Sorry, a bad typo. MTM applies to Canada, not the US.

Cheers,
Dean

----- Original Message -----
From: Dean Mikkelsen <dcmikkelsen at SHAW.CA>
Date: Tuesday, June 14, 2005 9:10 am
Subject: Re: [UMN_MAPSERVER-USERS] EPSG code for...

> Hi again,
> 
> MTM is defined for Canada. They are 3 degree Modified Transverse 
> Mercator projections. They will not apply to Canada.
> 
> For a reference see the following web-sites:
> 
> MTM:
> http://www.geod.nrcan.gc.ca/images/products/MTM.jpg
> 
> UTM:
> http://www.geod.nrcan.gc.ca/images/products/UTM.jpg
> 
> Both were referred to via:
> http://www.geod.nrcan.gc.ca/index_e/online_apps_e/appNtv2_e/appntv2_utm_e.html
> 
> Cheers,
> Dean
> 
> 
> 
> ----- Original Message -----
> From: "Christopher R. Thorne" <christhorne at SYMPATICO.CA>
> Date: Tuesday, June 14, 2005 7:36 am
> Subject: Re: [UMN_MAPSERVER-USERS] EPSG code for...
> 
> > Hello me again,
> > I finally tracked down the metadata for the data that was given 
> to 
> > me 
> > with the strange projection. Well it gets stranger. Here is what 
> I 
> > found. I have two shape files of the Los Angeles county
> > 
> > 1st shape file :
> > ----------------
> > Datum:NAD27
> > Units: Meters
> > Ellipsoid:Clark 1866
> > Projection: UTM, Zone 11
> > 
> >  * Possible EPSG codes found:
> > 
> > # NAD27(76) / MTM zone 11
> > <2020> +proj=tmerc +lat_0=0 +lon_0=-82.5 +k=0.999900 +x_0=304800 
> > +y_0=0 
> > +ellps=clrk66 +units=m +no_defs  no_defs <>
> > 
> > # NAD27 / UTM zone 11N
> > <26711> +proj=utm +zone=11 +ellps=clrk66 +datum=NAD27 +units=m 
> > +no_defs 
> >  no_defs <>
> > 
> > 2nd shape file:
> > 
> > Datum:NAD83
> > Units: Meters
> > Ellipsoid:Clark 1866
> > Projection: UTM, Zone 11
> > 
> >   * Possible EPSG Codes found:
> > 
> >   NONE FOUND.....
> > 
> > This makes me think that NAD83 with a Clark 1866 Ellipsoid is 
> not 
> > a 
> > valid projection. Am I on the right trake of thinking or is 
> there 
> > actually an EPSG code with:
> > 
> > <????> +proj=utm +zone=11 +ellps=clrk66 +datum=NAD83 +units=m 
> > +no_defs 
> > no_defs <>
> > 
> > Comments?
> > Chris
> > 
> > Christopher R. Thorne wrote:
> > > Hello Dean,
> > > 
> > > Dean C. Mikkelsen wrote:
> > > 
> > >> Hi Chris,
> > >>
> > >> Take a look at the following web-page.
> > >> I am leaning towards a problem now in defining which State Plane
> > >> Co-ordinate System is being used. i.e. one of the ones we are 
> > using is
> > >> wrong - we may actually be north or south of the current one. 
> > Now the
> > >> trick is to determine which one. A note to other readers 
> > epsg:4326 is
> > >> WGS84.
> > >>
> > >> Did you try reprojecting the NAD27 Layer with the NAD83 
> > definition? 
> > > 
> > > 
> > > Yes I did that and the layers switched positions.
> > > 
> > > Or
> > > 
> > >> with epsg:4326? What happens?
> > >>
> > > with setting the projection to the lat/long layers, they are 
> not 
> > found 
> > > in outer space, not within the world extent.
> > > 
> > >> http://www.wadetrim.com/resources/articles/sblocks.htm
> > > 
> > > 
> > > Thanks for the good reference. The reason why I got into this 
> > situation 
> > > was because I am four steps removed from the data provider. I 
> > only 
> > > managed to get the information that you already know and I was 
> > hoping 
> > > the information was correct. The other problem was that I was 
> > not sure 
> > > how to identify the issues, confidently. If not I will 
> > definitely push 
> > > for more information.
> > > 
> > > Cheers and thanks again,
> > > Chris
> > > 
> > 
> > 
> > -- 
> > Christopher R. Thorne, GIS Specialist
> > -
> > christhorne at sympatico.ca
> > Tel:(613)523-6593, Ottawa ON Canada
> > -----------------------------
> > 
>