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Solving 'Track Truncated' Reports

Solving 'Track Truncated' reports when loading Track Files from PNFs CD

Track Files on our PNFs CD are as recorded by the author when the walking route was researched. These are the complete Track File records without compression and for many of our walking routes these Track Files exceed 500 track points.

Many GPS units have a Track Memory limit of 500 track points and loading the full Track File which exceeds 500 track points into this memory will result in a 'Track Truncated' error report on your GPS unit and only the first 500 track points will be loaded. As some of our Track Files have as many as 1,400 track points you can lose a lot of information unless you modify the data before loading into your GPS unit.

Here's how I do it:-
Open GPS Utilty software on my PC with PNFs CD in my CD drive, having clicked the 'Exit' to leave the 'autorun' section of the CD.
In GPS Utility click 'File' and in the drop down menu click 'Open'
In the dialogue box select Trackpoints (trk,plt) file type and then select the Track File I want to open on the PNFs CD, then click Open.
The Track List box opens in GPS Utility listing the track points, then click on 'Track Summary' symbol for the Track Summary report.
If the 'Legs' number is above 500 then we need to 'smooth' the Track File down to below 500 Track Points (Legs) and here is how I do it:-
Walk! Peak District South Walk 25 Chatsworth the Peoples Aristocracy has 754 'Legs' (Track Points)
Click the Blue Box on the left to make it go + this selects the track
Click Tools and in the drop down menu click Generate Track Points
In the Track Dialog box set the Off Route distance to 1, meaning 1 metre, and click Retry
For Walk 25 this produces 504 Track Waypoints which will be near enough for me as I will only lose the last three points when I load the Track into Garmin 60 Track Memory. However I repeat the Generate Track Points, still at 1, and the Track is now reduced to 489 points; this is the most the 1 setting will reduce the number of 'Legs' and will now fit in my Track Memory as a complete Track.
If your first Off Route selection produces just over 500 Track Points then try repeating the selection again, this normally reduces the number of Track Points slightly. Of course you might be happy with a Track that has slightly more than 500 Track Points so that when you load it into your GPS memory the Track is Truncated but you are only losing those last few Track Points but your loaded Track will be more accurate than if you increased the Off Route distance to produce a Track of under 500 Track Points.
If the number of Track Waypoints in the Track Dialog box is still above 500, increase the Off Route distance to 2 and click Retry
Only the very longest routes will require you to increase the Off Route distance to 3, 4 or 5 metres before the number of Track Waypoints drops below 500
Then click the Compress Track button and OK, note the Track Summary now shows the new number of 'Legs' - Track Points.
Now load the compressed Track into your GPS unit.

Accuracy of compressed Tracks is very good for a 1 metre compression, getting slightly less accurate as the Off Route distance is increased to 2 metres, 3 metres etc, but you will get a full Track from Start to Finish in your GPS unit.

David Brawn
Author of GPS The Easy Way