[Proj] request help with Lambert Conic Conformal (2SP)

[Mikael Rittri]

Carl,
In fact, I don't think you are missing anything.

I made a quick back-of-an-envelope calculation - not using
proj, just a plain calculator - starting with the projection
origin, assuming 111120 meters per degree of latitude,
and 111120 * cos(lat) meters per degree of longitude.

For the test point, I got

Easting = 1408985 ft
Northing = 2341613 ft.

That's close enough to your (Carl's) result, with my simple method.

I may have made a mistake, but Rick: could you double-check your expected coordinates - I am pretty sure they are wrong.

Regards,

Mikael Rittri
Carmenta
Sweden
http://www.carmenta.com

16 aug 2012 kl. 05:30 skrev "Carl Godkin" <cgodkin at gmail.com<mailto:cgodkin at gmail.com>>:



On Wed, Aug 15, 2012 at 8:00 PM, Rick Graves <<mailto:gravesricharde at yahoo.com>gravesricharde at yahoo.com<mailto:gravesricharde at yahoo.com>> wrote:
Hey,

The good news is that Oregon is the last one I need to get working.  The bad news is I do not have it working yet.

Here is the metadata from the .prj that I got from the state:

PROJCS["NAD_1983_Oregon_Statewide_Lambert_Feet_Intl",
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["Lambert_Conformal_Conic"],
PARAMETER["False_Easting",1312335.958005249],
PARAMETER["False_Northing",0.0],
PARAMETER["Central_Meridian",-120.5],
PARAMETER["Standard_Parallel_1",43.0],
PARAMETER["Standard_Parallel_2",45.5],
PARAMETER["Latitude_Of_Origin",41.75],
UNIT["Foot",0.3048]],
VERTCS["NAD_1983",
DATUM["D_North_American_1983",
SPHEROID["GRS_1980",6378137.0,298.257222101]],
PARAMETER["Vertical_Shift",0.0],
PARAMETER["Direction",1.0],

I initialized proj as follows:

proj +proj=lcc +lon_0=-120.5 +lat_0=41.75 +lat_1=43.0 +lat_2=45.5 +x_0=1312335.958005249 +y_0=0.0 +units=ft

I assume something is not right.



I think there are two things wrong:
1. Your false easting is here given in feet while I believe proj always wants meters.  The number is about 400000m.  (See <http://trac.osgeo.org/proj/wiki/GenParms> http://trac.osgeo.org/proj/wiki/GenParms).
2. You didn't include an ellipsoid or datum so I'm surprised that proj worked at all since I get an error without +datum=NAD83 or +ellps=GRS80.

However, correcting both of those, I get  X=2344859.57 ft, Y=1434192.31 ft, which isn't what you want either.

Now I want to know what I am missing!  Let's hope someone cleverer than me answers.

carl
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