[GIS] How to get the Parameters for a Lambert conformal conic projection CRS in QGIS 2.6

coordinate systemqgis

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.

Best Answer

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

Related Question