Map-HST.txt ver 7.2e   MAP MAKING FROM TRACK HIST FILES

     The APRS mapmaking program MAPFIX can overlay any APRS track history
file onto a working map.  You can then use the cursor to draw in roads
over the track history points.   Since the track history points were taken
at regularly timed intervals, you should avoid the temptation to simply 
connect the points line-by-line, because there is no assurance that any 
particular point occurred exactly at an intersection or a turn in the road.

     Recently, I have added the F8 key which is a FIX-NOW command.  This
permits you to override the regular timing of GPS fixes, and force a GPS
fix at any time by simply pressing F8.  This is very valuable for making
sure that you get a good GPS fix at each intersection, checkpoint or 
other landmark while driving and building a track history.  

Here is a typical procedure for making maps from track histories:

   1) Set HSP-POSRATE to something like every 5 to 15 seconds or so.  
      This is so you get a steady stream of fixes.

   2) Everytime you want to mark an intersection or checkpoint or other 
      feature, press F8 to instantly update your GPS position.  This 
      will assure that you get a fix at that location.

   3) If you want to specifically mark that point with a label, then 
      press GO to bring the cursor to that location, and press 
      INPUT-ADD to add an OBJECT to your POSIT file giving it the name 
      of the location you want to remember.  The INPUT-ADD command will 
      ask you for the name of the object plus any comments.

   4) Alternatively, to avoid having to type in the name (while driving), 
      you can just hit the INPUT-SAVE command, and a serial numbered 
      object will be added to the position list.  If you can remember what 
      these sequential OBJects are, then unique names are not necessary.  
      Usually it is easy to remember these marks, since you probably 
      already have a paper map for the special event for reference.

Unfortunately, when you replay the track history file back in MAPFIX, all 
the dots look the same, but at least if you used F8, one of them will 
correspond to each marked location.  Later after you have integrated the 
map into APRS, then you can do a real REPLAY of the file, and these 
special checkpoints or marked locations WILL show up to verify the 
quality of the map...

An ALTERNATIVE to step 1 and 2 above, is to set your POSRATE to 10 
minutes, so that NO points go into the track history, EXCEPT for each 
time you press F8.  This gives you total control over what dots will be 
overlayed in MAPFIX.  In effect you are using your CAR AS A MOUSE in the 
real world and using F8 to "click" on each turn in the road!  The down 
side is that this method demands a LOT of driver concentration.  The UP 
side is that EVERY POINT was selected by you and all you need to do in 
MAPFIX is connect the dots!

In my opinion, if the map is big and you are doing a lot of driving, then 
the automatic high 5 to 15 sec rate will allow you to think about other 
things while driving without fear of missing a slight turn.  You can 
still mark any point with the F8, but the problems are figuring which dot 
is which when you go to build the map...  So in addition to just marking 
an intersection, you should also be sure to eventually drive through the 
same intersection on the other road to clearly show where the road is.
