[Proj] Using cs2cs to convert UTM/NAD27 to latlong/WGS84

Ed McNierney ed at topozone.com
Fri Oct 1 12:43:23 EDT 2004

Carl -

Eric's reply is a good solution, but your real problem is you're failing to specify the UTM zone.  UTM is not "a" projection, but a family of projections, and you need to specify +zone=11 as Eric did in order to completely specify the projection.  Technically, the "11" is an attribute of the projection, not of the coordinate point as you're using it.

	- Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242  

-----Original Message-----
From: proj-bounces at xserve.flids.com [mailto:proj-bounces at xserve.flids.com] On Behalf Of Carl Reisinger
Sent: Thursday, September 30, 2004 10:08 PM
To: proj at remotesensing.org
Subject: [Proj] Using cs2cs to convert UTM/NAD27 to latlong/WGS84

I have downloaded and built the proj-4.4.8 sources (also downloaded and un-tared into the nad directory prog-nad27-1.1.tar.gz before the build).
The build system is FreeBSD 4.9 running gcc version 2.95.4.

I am now trying to convert a series of coordinates that are in UTM and based on the NAD27 datum into latlong/WGS84.

I have been unable to get any result out of cs2cs. Example output with the environment variable PROJ_DEBUG defined:

$ sh -x example
+ cs2cs -E +proj=utm +datum=NAD27 +to +proj=latlong +datum=WGS84 -v
pj_open_lib(proj_def.dat): call fopen(/usr/local/share/proj/proj_def.dat) - succeeded
pj_open_lib(proj_def.dat): call fopen(/usr/local/share/proj/proj_def.dat) - succeeded # ---- From Coordinate System ---- #Universal Transverse Mercator (UTM)
#       Cyl, Sph
#       zone= south
# +proj=utm +datum=NAD27 +ellps=clrk66
# +nadgrids=@conus, at alaska, at ntv2_0.gsb, at ntv1_can.dat
# ---- To Coordinate System ----
#Lat/long (Geodetic)
# +proj=latlong +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0
pj_open_lib(conus): call fopen(/usr/local/share/proj/conus) - succeeded Ctable Conterminous United States 273x121: LL=(-131,20) UR=(-62.75,50.25)
pj_open_lib(alaska): call fopen(/usr/local/share/proj/alaska) - succeeded Ctable Alaska 529x249: LL=(-194,46) UR=(-127.875,77.125)
pj_open_lib(ntv2_0.gsb): call fopen(/usr/local/share/proj/ntv2_0.gsb) - failed
pj_open_lib(ntv1_can.dat): call fopen(/usr/local/share/proj/ntv1_can.dat) - succeeded
NTv1 393x177: LL=(-142,40) UR=(-44,84)
pj_apply_gridshift(): failed to find a grid shift table for
                      location (-5.3547203dW,40.6534808dN)
   tried: @conus, at alaska, at ntv2_0.gsb, at ntv1_can.dat
0300917 4502746 11      *       * 11.000

The location is Gerlach, NV if that matters at all.

Punting on cs2cs and using nad2nad, I get:

+ nad2nad -i utm=11,27 -o 83 -r conus
pj_open_lib(conus): call fopen(/usr/local/share/proj/conus) - succeeded 119d21'20.664"W 40d39'12.176"N

Now, I really don't know if that answer is correct but comparing it to that obtained from jeeep.com, it is different.

I would like to see the cs2cs work. Is there anything obvious in the output that I need to address?

Failing that, is the results from the nad2nad to be trusted?

Carl Reisinger

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