I'm working with ArcMap 10 and I have a feature points shapefile from the Florence (Italy) municipality open data (http://opendata.comune.fi.it/statistica_territorio/dataset_0040.html). Each point is an address point.

As I add it to the data frame a message says the data is missing spatial reference information and the points result in a wrong location. How can I understand which is the correct spatial reference of this shapefile and have the points in the correct location? I own other features of the same area with the correct coordinates (eg a layer with the streets of Florence). Coordinates system of these features is GCS_WGS_1984 Would that be of any use?

I followed these steps http://www.esri.com/news/arcwatch/0111/tip.html but couldn't get it working. I hope I didn't miss any older post posing this question. In case I did I apologize.

  • The dataset has a .prj, but it doesn't look like a legal Esri PRJ string to me (too many extras). Since it claims to be EPSG 3003, why not just rename the .prj to .prx, and define with 3003? – Vince Jul 14 '15 at 16:38
  • 2
    Melita says that the "semi_minor" parameter is causing the parser to fail -- if you remove the PARAMETER["semi_minor", 6356911.95], the .prj file should be readable. – Vince Jul 14 '15 at 16:46
  • Probably ought to tell the provider that their data isn't formatted correctly, too. – Vince Jul 14 '15 at 16:47
  • Thanks for the comments. Unfortunately my knowledge of geodetic systems (I don't really know the meaning of EPSG 3003) and file formats is quite limited. How could I remove that part? Which program should I use to do this and save it again as a .prj? – Michele Cordini Jul 23 '15 at 8:07
  • 1
    The .prj is a text file -- any text editor can be used (just be sure to leave it as one long string) – Vince Jul 23 '15 at 10:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.