3.1.2.5- FIXED POINTS

To give real world coordinates to centerline, you need to have at least a fixed station point. This is, a station point with real coordinates. You should add to survey data a line like this:

fix 0 575628 4476124 1250

As you can guess this fixed point is station 0 with UTM coordinates. You can have as many fixed points as you need. The more fixed points, the better. I usually write them at the beginning of survey data, so my final .th file could look like this:

survey irurixo -title "Irurixo Koba"
  centerline
  date 2005.02.26
  declination -3 degrees
  team "Mac Theknife"
  team "Juxe Euskalduna" # add as many team lines as you need
  units compass grad
  data normal from to length compass clino left right up down

  fix     0       575628  4476124 1250
  fix     42      575100  4476655 1310
  0       1       16.25   345     -10     1.00    0.85    6       1.60
  1       2       4.10    275     1       0.30    0.90    2       1.60
  (more survey data)

  endcenterline
endsurvey

Well, we are now ready to create our first thconfig file, so we can export an xvi (xtherion vectorial image) with our centerline data. This image will be loaded in map editor window as “Background image”.