David Stajan wrote:
PROJCS["AGD_1966_AMG_Zone_55", GEOGCS["GCS_Australian_1966", DATUM["D_Australian_1966", SPHEROID["Australian",6378160,298.25]], PRIMEM["Greenwich",0], UNIT["Degree",0.017453292519943295]], PROJECTION["Transverse_Mercator"], PARAMETER["False_Easting",500000], PARAMETER["False_Northing",10000000], PARAMETER["Central_Meridian",147], PARAMETER["Scale_Factor",0.9996], PARAMETER["Latitude_Of_Origin",0], UNIT["Meter",1]]My best attempt to define this using the proj.4 syntax is: PROJECTION "proj=utm" "zone=55" "units=m" "ellps=aust_SA" "lat_0=0" "lon_0=147" "x_0=500000" "y_0=10000000" "k_0=0.9996" "a=6378160" "rf=298.25" "pm=greenwich" END
David, I would suggest "+proj=utm +zone=55 +south +ellps=aust_SA". The +pm=greenwich setting is unnecessary since this is the default. It is imprudent to specify settings like lat_0, lon_0, x_0, y_0 and +k_0 that are implied by proj=utm and a zone. It is imprudent to doubly define the earth model - using both +ellps and +a, +rf. I note you missed the important +south modifier on your utm projection. Note that the projection as defined does not know how to switch to the WGS84 datum (if that is an objective). PROJ 4.5.0 and earlier will do a change of ellipsoid which may introduce unexpected shifts. PROJ 4.6.0 will assume no datum shift is needed. Finally, I hate the old syntax for PROJECTION blocks of putting each parameter on it's own line. Furthermore there are some issues with parsing it in esoteric circumstanes. I'd encourage: PROJECTION "+proj=utm +zone=55 +south +ellps=aust_SA" END Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [EMAIL PROTECTED] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | President OSGeo, http://osgeo.org
