UPPER COLCA PROJECT
Arequipa, Peru
GPS DATA
Colca GCPs - Point Shapefile.
From city centers, bridges, and other distinct point locations.Colca Roads - Point and Line Shapefiles..
GPS data gathered along some major roads in the Colca area..These Global Position System points were gathered using a Trimble Geoexplorer II in 2001 and 2002. The points were differentially corrected using the AREQ base station about 100km to the south. The error for these GPS points is approximately 1-2m both horizontally and vertically, so they make good Ground Control Points.
All data was gathered in the WGS84 datum, decimal Lat/Long.
Note that most Peruvian maps are in PSAD 1956 Datum (La Canoa). If these points appear about 400m to the north-east of where you expect, this is probably the reason. Use these GPS points to reference your data to WGS84, the standard world system.