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I am currently having some trouble adding the CRS to a vector file that I want to re project to WGS84/UTM. The shapefile is using Lambert Conformal Conic Projection; ITRF92 horizontal datum and GRS 1980 ellipsoid according to the metadata.

I will like to know how to define the original CRS since in QGIS Lambert CCP/ITRF92 does not appear as part of the available reference systems. The full definition is:

GEOCCS["ITRF92",DATUM["International_Terrestrial_Reference_Frame_1992",SPHEROID[‌​"GRS
1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6651"]],‌​PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["metre",1,AUTHORITY["EPSG","9‌​001"]],AXIS["Geocentric
X",OTHER],AXIS["Geocentric Y",OTHER],AXIS["Geocentric Z",NORTH],AUTHORITY["EPSG","4914"]]

Projection: Lambert conformal conic

Standard parallel: 17.5

standard parallel: 19.5

longitude of the central meridian: -102.000000 
latitude of the origin of the projection: +12.000000

false easting: 2 500 000
false northing: 0

The data's location is in Mexico.

david_p
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Nadia
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    Well, the given definition is wrong--ITRF92 does not use the Clarke 1866 ellipsoid. Can you post the projection parameters and the data's location? Maybe we can come up with what coordinate system it should be. – mkennedy Dec 11 '14 at 22:42
  • Hi! thanks for answering...this is the info: GEOCCS["ITRF92",DATUM["International_Terrestrial_Reference_Frame_1992",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6651"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Geocentric X",OTHER],AXIS["Geocentric Y",OTHER],AXIS["Geocentric Z",NORTH],AUTHORITY["EPSG","4914"]] – Nadia Dec 12 '14 at 00:00
  • Projection: Lambert conformal conic Standard parallel: 17.5 standard parallel: 19.5 longitude of the central meridian: -102.000000 latitude of the origin of the projection: +12.000000 false easting: 2 500 000 false northing: 0 – Nadia Dec 12 '14 at 00:04

1 Answers1

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In QGIS, goto Settings -> Custom CRS, and Copy from existing CRS.

take a lcc projection based on WGS84, like EPSG:3762

+proj=lcc +lat_1=-54 +lat_2=-54.75 +lat_0=-55 +lon_0=-37 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs

and replace the values to your system:

+proj=lcc +lat_1=17.5 +lat_2=19.5 +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

I took ITRF92 and WGS84 as identical. See this page for more information about that:

ftp://itrf.ensg.ign.fr/pub/itrf/WGS84.TXT

AndreJ
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