As MartinS wrote, you will definitely need some reference points, but they do not need to be stations. In the case, if there are no survey data - all you need to do is just to scale each scrap properly. I would do following steps: 1. Put some grid on the scanned images according to scale. Ideal is some real coordinate grid like UTM, but also some local coordinate system is OK. 2. Then set X Y coordinates of two real points and two points on the JPG image for each scrap in the section - you have to set them in "Scraps" tab in map editor - under "picture scale points" and "real scale points". In fact you have to calibrate the scraps same way, as you do it for cross-sections (with exception, that projection is plan). See Wiki for details: http://therion.speleo.sk/wiki/doku.php?id=tbe:wiki3#cross_sections After calibration - each scrap should be displayed on the correct place and in the correct scale. If you will enter real coordinates in some, UTM grid - you have to add "-cs UTM32" option to the scrap, that it will know where to put the scrap. HTH, S. Quoting Jonathan Prouty <dormat@gmail.com>:
I decided to digitize an old map of one of my favorite caves. The JPG of the entire original map was too big for therion to load, so I cut it up into smaller images that will load.Tracing the map and compiling it worked perfectly for the first section that I digitized (section_1.th2). I moved onto the second one, traced the old map same as before (section_2.th2). All that is pretty straightforward.
The problem arises when I try to join scraps from section 2 with scraps from section 1. The join fails miserably. I tried to follow the instructions from the wiki (http://therion.speleo.sk/wiki/doku.php?id=tbe:wiki4#importing_maps), but it seems the instructions are geared towards joining unsurveyed data with surveyed data. I don't see how to join unsurveyed scraps with other unsurveyed scraps. I have no "fake" data like the instructions suggest.
I've included links to an image of a portion of the old map I'm digitizing and to a PDF that therion spit out. Comparing the two will make the problem very apparent. I'm sure there is a pretty straightforward solution, I simply don't know it. Thanks in advance in for the help!
http://www.talkingnerdy.com/jonny/images/slices.png http://www.talkingnerdy.com/jonny/images/byers.pdf
-Jonny
P.S. Just in case it wasn't clear, I don't have access to any of the original survey data. The cave was surveyed in the 60s. I'd be surprised if the original data still exists.
-- ^v^ ^v^ ^v^ Take nothing but pictures, ^v^ Leave nothing but footprints, ^v^ Kill nothing but time. (**)