On May 14, 9:13 am, wrote:
snip
I also suggested to the company that they offer an aviation tracking
option that reports every minute instead of every 10 minutes, but was
told the unit takes 4 minutes to get each GPS fix. I guess that's how
it last so long on a set of batteries. I then suggested they offer an
every 4 minute tracking option and was told they will think about it.

Makes me wonder what is going on during that 4 minutes. are there
inaccuracies introduced by the fact that we are moving faster than a
hiker? how about the fact that we change altitude over that 4
minutes? Is it averaging a bunch of signals? Is it gathering
components of a single fix? Maybe it gets an instant fix, and then
waits for an opening to upload to the satellite? Has anyone ever
compared the spot time stamped location to an IGC trace temporally? In
other words, even though there is a lag in getting the fix from spot,
I wonder if the time it puts on the fix is accurate. If you flew over
some point of interest and pushed the OK button to mark it would you
get the right position 20 minutes later, or some random in between
position n minutes later?

Matt