I hope nobody thinks this is an attempt to get someone else to do my homework for me, but :-) I have a big MapInfo map of an archaeological site in upper Myanmar/Burma, based originally on existing metric non-earth survey point data which came in eastings and northings. I have a point on this grid whose Lat and Long are known. This map is augmented with material from old 1940s maps (the only ones available) and aerial photos. I now want to survey areas on the edge of my site, with a hand-held GPS. I figure that as I am using the database for archaeological analysis and not trying for surveyor-type accuracy, my new locations will be fine even if they're a couple of hundred metres off, so hand-held GPS is ok. But here's the problem. How do I reconcile the metric UTM readings from my GPS with the metric readings from my map grid? My first thought was to take UTM readings from known points, which are also on the non-earth map made from the original survey, and do the maths (a subject I usually rely on MapInfo and Excel to do for me!) If my non-earth point at E 5,000m /N 10,000m is, say, UTM E 657747 / N 2344792 on the GPS, any other UTM point east or north of that datum can be converted to my non-earth coordinates by subtracting the number I first thought of, as it were. 1. Does that make sense? 2. Is there a better way? A formula? Bob H ---------------------------------------------------------------------- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
