1

I'm using QGIS 1.8.0 and have some shapefiles with a "User Defined CRS" which I don't recognize. Is anyone able to recognize it?

Here is an image of the settings I see on QGIS. enter image description here

Improve this question
4
  • 3
    Please tell us what you mean by "recognize it": after all, it appears that your software has a complete set of parameters for this CRS, so what is there left to determine?
    – whuber
    Commented Oct 22, 2013 at 14:10
  • The thing is that I want to upload a delimited text layer with some points which have lat/long as CRS. So I have to convert those coordinates to the CRS of the whole map. If I do the other way around (convert the map to lat/long) it looses resolution (strangely).
    – user20159
    Commented Oct 22, 2013 at 14:32
  • 1
    You might get more value out of asking that question about how to import the text file using this custom CRS, rather than asking about something that might (at best) only lead to a work-around of your problem.
    – whuber
    Commented Oct 22, 2013 at 14:36
  • Related: gis.stackexchange.com/questions/75167/….
    – AndreJ
    Commented Oct 23, 2013 at 8:37

3 Answers 3

Reset to default
6

It's EPSG:6372, a projection for Mexico, defined by the Instituto Nacional de Estadística y Geografía (INEGI).

Improve this answer
5
  • Do you know how to convert from that CRS to lat/long?!
    – user20159
    Commented Oct 22, 2013 at 14:47
  • 1
    @user20159: The same way that you would convert between other CRS's that QGIS supports: Select the layer, click "Layer / Save as" and choose "EPSG:4326" as the target CRS.
    – Jake
    Commented Oct 22, 2013 at 14:54
  • I mean to convert one punctual value (like 2799808, 1316921) to lat/long? I have a list of punctual values that I have to convert from one system to the other...
    – user20159
    Commented Oct 22, 2013 at 15:08
  • @user20159: You can use the cs2cs command line tool from the GDAL tools for that: Run cs2cs +proj=lcc +lat_1=17.5 +lat_2=29.5 +lat_0=12 +lon_0=-102 +x_0=2500000 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +to +init=epsg:4326 and then enter your coordinate 2799808 1316921. It will return 99d2'25.637"W 23d51'30.394"N 0.000. You can add the option -f "%.6f" to the command to get output in decimal degrees.
    – Jake
    Commented Oct 22, 2013 at 15:14
  • I don't have that tool, but for further reference I found this site, pretty cool: twcc.free.fr. It converts almost every CRS. For EPSG:6372 I used SR-ORG:6700: Mexico INEGI Lambert Conformal Conic. Thanks so much Jake!
    – user20159
    Commented Oct 22, 2013 at 16:07
2

That looks like EPSG::6361 a.k.a. 'Mexico LCC'

The EPSG Registry is good for finding the common names for different systems and datums.

Improve this answer
1
  • 1
    Almost: EPSG:6361 is a "conversion", not a projection: It lacks the specification of the ellipsoid, which is present in the OP's proj4 string. It looks like the projection in question is EPSG:6372, which uses the same projection parameters, but also specifies the use of the GRS80 ellipsoid.
    – Jake
    Commented Oct 22, 2013 at 14:46
0

your proj.4 string says it's a lambert conformal conic project with parallels at 17.5 ˚and 29.5˚ north, latitude origin at 12˚ north and longitude set at -102 ˚ west, false easting of 2500000, is using the ellipsoid of GRS80 and uses meters as a unit of measurement. Read about Proj.4 parameters here: http://trac.osgeo.org/proj/wiki/GenParms

Looks like it's centered in the Pacific Ocean off central America somewhere.

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.