TransDEM Forum

I have a large scale plan, which I think has not been scanned on a flatbed scanner, but simply photographed from a camera above a table. The quality of the jpg image is great, but I've found that it did not georef properly when just using the 3 points. It must be slightly distorted.
I tried using the "Georeference with Triangle Network" option and that seemed to work OK. I've set the co-ordinate system to OSGB, with the grid square set to SK (for Nottingham) and I can enter the coordinates easily, after the first 2 or 3, the values are calculated automatically, just a case of adjusting them slightly to match the distorted map.
But I noticed the Lat/long reading on the bottom status bar is way off what I expected (approx 53N 2W - I get 55N 6E) and when I "Convert to UTM" and try to join with my existing maps I get a message it is in a different UTM zone, and it appears 100s of miles away rather than almost in the middle of my existing map group.

Am I doing something wrong or is it a bug with the program?

Thanks

I had tested it with a number of coordinate systems but not with the O/S grid and grid square IDs active. I have to try it out myself and see what happens.

Thanks for the quick reply.
I should have said it works OK with the normal "Georeference" (Ctrl-R) Command, the map appears exactly where expected apart from the slight mis-match, which was what alerted me to the distortion in the first place. This is why I suspect a bug in the program...

Did you try O/S coordinates in the full value range? Hundred thousands instead of grid square letters?

That seems to work for me. Grid square letters do not, apparently. Not with the triangular method. Needs investigation.