[Cdt-l] Ley's CDT on Google maps update....Waypoint, Route suggestions?

Frank Gilliland frankgilliland at comcast.net
Fri Jan 1 23:34:34 CST 2010

From Postholer:
I've recreated the map based on a 2,750 mile trail which is in line with 
what Jonathan states is the approximate length, 2700-2800 miles.


This data can now be easily converted to routes, waypoints, etc, with 
mileage approximations. Before I do this, what would be the best format? 
Just waypoints? Just routes? Number of waypoints per route, number of 
routes, etc? What is the best trail direction, north to south?



It is nice having just the track of the trail available in a format that can be loaded onto a gps as well.  So with that here is a long ramble about gps file info pertaining to Garmin:

I have also made the Ley map into a track file from his posted GoogleEarth file.   I have it available for any one to use upon request.  (Would you like the raw data?)

email off line:    frankgilliland  < at >   comcast.net

I also have a copy of Triple o's (OOO's) track files (see Dec 2009 previous post for more info) [Cdt-l] GPS and Maps (howzitdone?)   and a bunch of waypoints (including the Ley map waypoints, some of my waypoints and from other hikers such as from "James" and FreeFall).  The Triple "O" track files are broken into four segments and will only fit onto the Oregon/Colorado units.  I am in the process of breaking them down into smaller segments that will fit onto the etrex series.  These files also include the NEW Crazy Cook route, the Columbus, Butte, and Anaconda routes and various alternates.  Of course it goes without saying that this data is not all field checked.  But, several folks have used it with good results.......


The format used for Garmin is .gdm   Garmin and many other programs also use the .gpx format.  .gpx is turning into a universal format.

I generally keep the waypoint file, the track file and map files separately in different .gdb or.gpx files


Garmin is both restrictive on the how data is handled and the size of the files.  

For the HCx series:

-For instance the max number of map segments is 2025 loaded on the sd card  (preloaded Garmin sd card has the entire US)
-Max number of track files is 20 with a max number of points not to exceed 500 for each of the 20 (tracks are loaded into the internal memory.  So for the entire CDT I broke the track into 2 to 4 segments per state and filtered them down to under 500 points.
-Waypoint limit is 500 or 1000 based on the model stored in the internal memory.
-And POI points are only limited to the remaining space on the sd card.  POI points are more or less converted waypoints.  Neat thing about using poi points is that they are stored on the sd card and then you can add waypoints as you go in the field.
Routes are another story and I don't mess with them to much.  Mostly good for car travel use.

The new Colorado and Oregon series can handle much larger files:

200 tracks of 10,000 points
1,000 waypoints
maps are handled differently and some have the entire US preloaded on the unit.
50 routes


Now the next step i am investigating  the process of creating "transparent" overlay map files of the track files data.  These "map" files (.img) can be loaded on top of the topo map segments.  They can be turned on and off and take up very little memory and are not then limited in size or quantity as are the track files.  (in the HCX series you still have to be below the 2025 map segment limit for ALL map segments)

I have played some with this but am in need of some help.  I hope to have the map files online on someones site before the start of the hiking season.

End of ramble for now more info later.  Feel free to contact me or send you raw data.  

Frank "StarMan" Gilliland
Denver, CO 

frankgilliland  < at >   comcast.net

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.backcountry.net/pipermail/cdt-l/attachments/20100101/7dcbc34b/attachment.html 

More information about the Cdt-l mailing list