convert x,y to lat,long

I have location points that are stored in x,y according to the local
GIS standard (NC State Plane 1983, I believe).

I'd like to convert them to lat,long, using an unattended script. I
have MapWindow GIS, and it provides this in the projection file for
this data that seems to imply some constants I could use to calculate
the lat,long from a given x,y.

+proj=lcc +lat_1=34.33333333333334 +lat_2=36.16666666666666
+lat_0=33.75 +lon_0=-79 +x_0=609601.2199999999 +y_0=0 +ellps=GRS80
+datum=NAD83 +to_meter=0.3048006096012192 +no_defs

Can I plug these into some sort of formula, and use that formula/
function on my x,y data to get lat/long?

Corpscon is a free conversion program developed by the USACE.

Try the open-source ogr2ogr utility from OGR library (http://
fwtools.maptools.org/)


Here's an example that converts your state plane soordinate input to
lat long values

Step1: convert your CSV to a shapefile. You can use gen2shp utility
(www.intevation.de/~jan/gen2shp/ )

gen2shp pointshapefile.shp points < input.csv

Step2: reproject your shapefile to geographic projection

ogr2ogr -s_srs EPSG:2264 -t_srs EPGS:4326 pointshapefile.shp
output.shp

you can invoke this from a shell script and run it unattended.

-Ujaval
http://gisindia.blogspot.com

cwh@pobox.com wrote:

Try the open-source ogr2ogr utility from OGR library (http://
fwtools.maptools.org/)


Here's an example that converts your state plane soordinate input to
lat long values

Step1: convert your CSV to a shapefile. You can use gen2shp utility
(www.intevation.de/~jan/gen2shp/ )

gen2shp pointshapefile.shp points < input.csv

Step2: reproject your shapefile to geographic projection

ogr2ogr -s_srs EPSG:2264 -t_srs EPSG:4326 pointshapefile.shp
output.shp

you can invoke this from a shell script and run it unattended.

-Ujaval
http://gisindia.blogspot.com

cwh@pobox.com wrote: