On Tue, Feb 28, 2012 at 10:05:46AM -0700, we recorded a bogon-computron collision of the <[email protected]> flavor, containing: > On Mon, Feb 27, 2012 at 03:23:55PM -0800, we recorded a bogon-computron > collision of the <[email protected]> flavor, containing: > > I have many lon-lat coordinates in decimal degree format that are to be > > converted to spcs Nevada East Zone (FIPS: 2701, ADS: 4601, UTM Zone 11), > > NAD83, US survey feet or, as the PROJ_INFO in that location has it: > > > > name: Transverse Mercator > > proj: tmerc > > datum: nad83 > > ellps: grs80 > > lat_0: 34.75 > > lon_0: -115.5833333333333 > > k: 0.9999 > > x_0: 200000.00001016 > > y_0: 8000000.000010163 > > no_defs: defined > > > > The command I propose to use is: > > > > cs2cs +proj=latlong +datum=NAD83 +to +proj=utm +zone=11 +datum=NAD83 > > > > Is this correct? > > No. Nevada East Zone State Plane Coordinate System is not the same as > UTM, Zone 11 (even though it may lie in UTM zone 11). Your command line > will > return UTM coordinates in meters easting and northing, not SPCS coordinates > in > US survey feet. > > What you want is to tell cs2cs to use the EPSG number 3421 > as the target coordinate system. From the PROJ.4 epsg file, that means: > > # NAD83 / Nevada East (ft US) > <3421> +proj=tmerc +lat_0=34.75 +lon_0=-115.5833333333333 +k=0.9999 > +x_0=200000.00001016 +y_0=8000000.000010163 +ellps=GRS80 +datum=NAD83 > +units=us-ft +no_defs <> > > which you can see matches your PROJ_INFO information. > > (On my system, the EPSG database for PROJ.4 is in /usr/local/share/proj/epsg) > > You should use this command line instead: > > cs2cs +proj=latlong +datum=NAD83 +to +init=epsg:3421
For what it's worth, if you are already in a GRASS session in the target location, you can always use the following command line to get lat/lon converted to the location's coordinate system: cs2cs +proj=latlong +datum=NAD83 +to `g.proj -f -j` g.proj -j prints out the correct PROJ.4 format coordinate system specification for the current location. You'll find that g.proj -j in your location will print out the same data as the epsg:3421 entry. -- Tom Russo KM5VY SAR502 DM64ux http://www.swcp.com/~russo/ Tijeras, NM QRPL#1592 K2#398 SOC#236 http://kevan.org/brain.cgi?DDTNM "And, isn't sanity really just a one-trick pony anyway? I mean all you get is one trick, rational thinking, but when you're good and crazy, oooh, oooh, oooh, the sky is the limit!" --- The Tick _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
