[Xastir] Converting State GIS Maps

[Tom Russo]

On Wed, Mar 31, 2004 at 04:26:20PM -0500, a Mr. Richard Feyler of Fort Lee, New Jersey <dpg at coe.neu.edu> writes 'Dear Rosanne Rosannadanna':
> 
> I know this is a little off topic, but with all this discussion about
> maps, maybe the answer will be helpful for somebody else.
> 
> I am trying to use the lovely, free ESRI maps from the Massachusetts GIS.
> (www.state.ma.us/mgis). These are in MA State Plane coordinate system
> (FIPS 2001), so I need to convert them using the shpcs2cs utility.
> However, the syntax that I have been using is not working:
> 
> shpcs2cs +proj=nad83:2001 +datum+nad83 +to +proj=latlong +datum=nad83

I believe, but cannot be sure, that you need to use "+init=nad83:2001"
and not "+proj=".  At least, if I use the normal cs2cs program that
comes with proj4 that particular combination lets me enter data and
does some kind of conversion.

Unfortunately, I've never used a shapefile in a state plane system, and don't 
have a way of verifying that it's the right way to go.  But you might try

  shpcs2cs inshape outshape +init=nad83:2001 +to +proj=latlong +datum=WGS84

and see if it produces a shapefile that, for example, lines features
up correctly with terraserver images or something.

I'd say you might be better off trying to use ogr2ogr for this
purpose, but for the life of me I have no idea what WKT to use (don't
see an obvious EPSG number for that transformation).  Gerry might know?

-- 
Tom Russo    KM5VY     SAR502  DM64ux         http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 http://www.qsl.net/~km5vy/
 "It is inhumane in my opinion to force people who have a genuine
  medical need for coffee to wait in line behind people who apparently
  view it as some kind of recreational activity."  -- Dave Barry