[OSM-newbies] How to convert NAD83 to latitude/longitude?

[Gabriel Ebner]

On Thu, Dec 27, 2007 at 04:04:00PM -0700, Kelly Jones wrote:
> I found some public domain data I want to upload to OSM, but can't
> seem to convert the NAD83 format it's in to latitude/longitude. I know
> it should be easy, but even things like:

It's not NAD83 that's giving you troubles, but the particular projection the
data is in.  NAD83 is almost exactly the same as WGS84 (at least for this
century).

> http://www.ngs.noaa.gov/cgi-bin/spc_getgp.prl
> 
> are giving me ridiculous answers.

This page doesn't seem to accept both NAD83 and feet, so that's to be
expected.

> OGRFeature(schoolLocation):23
>   SCHOOLTYPE (String) = HIGH
>   SCHOOLNAME (String) = RIO GRANDE
>   POINT (1507003.249 1473733.624)
> 
> I know the correct answer for this item is approximately latitude
> 35.052536, longitude -106.69394, but am not sure how to do this
> translation for all items in the shapefile.

How about the following?

$ echo 1507003.249 1473733.624 | invproj -f %f +init=epsg:2258
-106.695765     35.049850

According to the data in OSM, it's on the other side of the road as the
correct location.  Is that accurate enough?

>From what I see, you're already using OGR.  Have you tried the following?  It
should convert the shapefile with state plane coordinates into a shapefile
with WGS84 coordinates.

$ ogr2ogr -t_srs EPSG:4326 shapefile_wgs84.shp shapefile.shp

  Gabriel.