[Gpsbabel-misc] Garmin eTrex track data precision

[James F. <jf...@so...>]

I am using GPSBabel to offload the (active) track from Garmin eTrex
receivers. When I look at the position data I see that there appears
to be a rounding/precision effect such that the smallest recordable
horizontal position change is ~2.2 meters. This is not very useful
given what I would like to use the receivers for and it doesn't match  
the
Garmin protocol information I have been able to find on line which  
suggests
that lat lon are recorded as a signed long integers: which leads me to
expect that the precision should be ~0.02 m? It seems that the lat lon
data are only being recorded/read/reported using 3 of the available 4
bytes? I am guessing that the problem is on the Garmin firmware side,  
and
that for some reason they are only using the first 3 bytes, but
I wanted to confirm that GPSBabel is reading and reporting all off the
available numerical precision from the eTrex tracks? Anyone got any
suggestions?

(using GPSBabel 1.2.7 on XP and eTrex firmware 3.30)

many thanks

James