My friend Chris has converted the USDA Forest Service 2008 trails Shapefile layer into GPX files and loaded them onto an ftp site for VFTT use. A few notes from Chris on the conversion:
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A few notes on this data...
* There are 396 trails listed in the database. They have been convert into an equal number of individual GPX files plus an extra GPX file which contains
them all in one file ("00 - AllTrails.gpx"). There is also a compressed ZIP file ("00 - AllTrails.zip) which can be used to download all GPX files at once.
* The original coordinate system was "New Hampshire State Plane, NAD83, Feet". Coordinates have been converted to "Geographic, WGS84, Decimal degrees".
* There are two trails called "Square Ledge Trail". The GPX files have been renamed to add (Passaconaway) and (Pinkham) to distinguish them.
* The GPX files were named using the original database name. No attempt was made to correct misspellings (and there are a bunch of them).
* The trail data quality seems to fall into two categories, those trails that have had new data collected and those trails that were digitized off of the
USGS topo maps. You can usually tell them apart by looking at how smooth the trail data is when plotted. The trails that look particularly smooth have
been digitized off of the paper and are not to be trusted at all. The new data is as good as the data I have collected myself with a fairly good GPS.
* Although MyTopo.com was kind enough to provide me with the Terrain Professional conversion software and host the data on their ftp site, they are not responsible
for the data and should not be contacted in regards to it.
* Feel free to share the ftp link but if you do, please copy the notes when you share the link.
* It is probably best to keep the number of online versions of this data to a minimum so it can be updated and fixed as is required.
* If you need to get in touch with me in regards to this data, you can reach me through my GMail.com account. The account name is "HikesNH".
* ALTHOUGH EVERY ATTEMPT HAS BEEN MADE TO CONVERT THE DATA PROPERLY, IT IS OF UNKNOWN QUALITY AND SOME OF IT IS KNOWN TO BE BAD. MAKE SURE
YOU HAVE BACKUP MEANS OF NAVIGATION AND KNOW HOW TO USE THEM. USE THIS DATA AT YOUR OWN RISK.
Link:
ftp://ftp.mytopo.com/nhtrails
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Chris
Dec 10, 2010