[Proj] request help with proj

[Noel Zinn (cc)]

Foot/meter problem maybe?  72030/21966.03 ~= 3.279 ~= number of feet in a meter

Noel Zinn, Principal, Hydrometronics LLC
+1-832-539-1472 (office), +1-281-221-0051 (cell)
noel.zinn at hydrometronics.com (email)
http://www.hydrometronics.com (website)


From: Rick Graves 
Sent: Thursday, August 02, 2012 8:44 AM
To: PROJ.4 Projections Discussions 
Subject: [Proj] request help with proj

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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