====== 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".