[Proj] request help with proj

Eric Miller EMiller at dfg.ca.gov
Thu Aug 2 10:44:37 EST 2012


Try +units=us-ft.

See, proj -lu
-- 

Eric G. Miller
Team Lead
Natural Resources Management Applications
California Department of Fish and Game


>>> On 8/2/2012 at  6:44 AM, Rick Graves <gravesricharde at yahoo.com> wrote:
> Hey,
> 
> My northing numbers are way off, so I must be doing something wrong.
> 
> I want to convert lat/long to the following coordinate system:
> 
> PROJCS["NAD_1983_StatePlane_New_Hampshire_FIPS_2800_Feet",
> GEOGCS["GCS_North_American_1983",
> DATUM["D_North_American_1983",
> SPHEROID["GRS_1980", 6378137.0, 298.257222101]],
> PRIMEM["Greenwich",0.0],
> UNIT["Degree",0.0174532925199433]],
> PROJECTION["Transverse_Mercator"],
> PARAMETER["False_Easting",984250.0],
> PARAMETER["False_Northing",0.0],
> PARAMETER["Central_Meridian",-71.66666666666667],
> PARAMETER["Scale_Factor",0.9999666666666667],
> PARAMETER["Latitude_Of_Origin",42.5],
> UNIT["Foot_US",0.3048006096012192]]
> 
> I am initializing proj as follows:
> 
> proj +proj=tmerc +lat_0=42.5 +lon_0=-71.66666666666667 +k=0.9999666666666667 
> +x_0=984250.0 +y_0=0 +Units=Foot_US
> 
> I have a spot in SE New Hampshire, along the southern border with 
> Massachusetts, close to the SE corner:
> 
> -71.32228851666666 42.69722980277778
> 
> If you give 42.69722980277778, -71.32228851666666 to http://maps.google.com/, 
> it will show you a spot in New Hampshire (but gives a closest address in 
> Massachusetts just across the border, no big deal).
> 
> From a shape file that I got from New Hampshire, the bounding box is as 
> follows:
> 
> 745473.8751627404, 72029.90624999696, 1242053.0000937672, 1023283.999999998
> 
> (The coordinate system info above is from the prj file.)
> 
> So for a spot near the southern border, I am expecting a northing close to 
> 72030 (72,030), but I am getting 21966.03 (21,966).
> 
> My easting numbers are closer but not right on.
> 
> (I am using proj rel. 4.7.1, 23 September 2009, which came with ubuntu 
> 12.04.)
> 
> If someone can see what I am doing wrong, I would appreciate some guidance.
> 
> Thanks,
> 
> Rick Graves




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