Mwape, I do think you are dealing with the Robertson Projection. I think you will find that the negative is to the right on your maps, positive to the left, and also negative to the north and positive to the south.
If that is the case you will have to convert to a normal Cartesian system before attempting any transformation to UTM and having a recognizable set of reference point common to the maps and current maps of the area will be necessary. There are a few survey companies in South Africa (unfortunately I do not have any contact information) that have converted from Robertson to UTM for some clients when I was consulting. Hopefully someone else monitoring the forum may be able to provide you with further information on the coordinate system. I last had to convert from Robertson to UTM years ago. There was also a slight angular rotation of the grid as well if I remember correctly. Hopefully you will have river courses, old mine pits or other features that can be used to at least get close to the correct conversion from your maps to present day UTMs. Good Luck, Rob From: [email protected] [mailto:[email protected]] On Behalf Of Mwape Somanje Sent: Tuesday, June 17, 2014 8:48 AM To: Geosoft Oasis montaj and Target Subject: RE: [geonet] Converting Local Coordinates to Projected UTM Coordinates Hi Rob The coordinates are actually reversed, Y is the Easting and the X the Northing. Worse off is the negative sign, not sure what that means. Regards Mwape > From: [email protected]<mailto:[email protected]> > To: [email protected]<mailto:[email protected]> > Subject: RE: [geonet] Converting Local Coordinates to Projected UTM > Coordinates > Date: Tue, 17 Jun 2014 13:54:09 +0000 > > Mwape, > > It is possible that you may be accessing data in a coordinate projection that > was known as the Robertson Projection. This is a unique local projection that > is poorly documented. It was a projection popular with the military in some > African countries during that period and was also used by some mining > companies. It can be very confusing to sort out. > > Can you verify that the Y direction is actually N-S and not E-W? Similarly > that the X direction is actually E-W and not N-S? If I remember correctly, > the Robertson Projection reversed X & Y coordinates in addition to applying a > sign reversal (-ve to the north and east). Units are very probably feet but > you will need to verify as metres were also used. > > Suggest you verify the actual grid coordinate orientation using landmarks or > road intersections that may appear on the maps and on recent satellite > imagery or topographic maps. > > Good luck, it can be a real challenge to convert to UTM if the original data > is in the Robertson Projection. > > Rob Hearst M.Sc., P.Geo, P.Geoph. > Chief Geophysicist > Areva Resources Canada Inc. > Tel:306-343-4049 > Cell: 416-407-6355 > Fax:306-343-4632 > [email protected]<mailto:[email protected]> > > • Before printing this e-mail think if it is necessary > > AREVA group > THIS EMAIL COMMUNICATION IS PRIVATE. IF YOU ARE NOT THE INTENDED RECIPIENT, > PLEASE NOTIFY ME AT THE TELEPHONE NUMBER SHOWN ABOVE OR BY > RETURN EMAIL AND DELETE THIS COMMUNICATION AND ANY COPY IMMEDIATELY. DO NOT > FORWARD IT. THANK YOU. > > > -----Original Message----- > From: [email protected]<mailto:[email protected]> > [mailto:[email protected]] On Behalf Of mwape_somanje > Sent: Tuesday, June 17, 2014 2:35 AM > To: Geosoft Oasis montaj and Target > Subject: [geonet] Converting Local Coordinates to Projected UTM Coordinates > > Dear All > Am working on historical exploration plans for a project in Zambia that was > worked on by some RST company in the 1950 - 1960s. Unfortunately they were > using a local coordinate system that I do not understand for instance the > coordinate Y-10 000, X+25 000. I want to georefference the plans in UTM. Is > there a way to convert them in Target or any other formula? Someone told me > the coordinates are in Loc 29 and in feet. > Thanks > Mwape > --- > > Forum archives can be accessed here: > http://lyris.geosoft.com/read/?fourm=geonet > You are currently subscribed to geonet as: > [email protected]<mailto:[email protected]>. > To subscribe or unsubscribe from any of our forums, select the User Forum > selection on the Geosoft Community page: > http://www.geosoft.com/support/community > > --- > > Forum archives can be accessed here: > http://lyris.geosoft.com/read/?fourm=geonet > You are currently subscribed to geonet as: > [email protected]<mailto:[email protected]>. > To subscribe or unsubscribe from any of our forums, select the User Forum > selection on the Geosoft Community page: > http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]<mailto:[email protected]>. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community
