[aprssig] KC8UCH balloon over western PA right now, reaching NE Maryland by 10am

[Wes Johnston, AI4PX]

You'd probably want some sort of logic that kept the GPS power on
during the descent phase right?  Of course after it hits ground and
the tiny trak or open track modem device has a known position, there
would be no need to run the GPS any more.  W/o it running the radio
beacon could last a lot longer.

1)run GPS every 10 minutes for two minutes during ascent.  Tracker
should only beacon when gps data is valid.
2)run GPS continuously during descent, tracker beacons every 60 seconds simplex.
3)shut GPS off after landing.  Tracker beacons every 10 minutes with a
normal mobile path.

Since most trackers only have two mode, maybe a way to shut off the
GPS would be via impact sensor of some sort.  Modes 1 and 3 are very
similar, maybe there's room here for a compromise that would allow
this idea to work with only two modes?

Wes


On 4/1/07, Bob Bruninga <bruninga at usna.edu> wrote:
> > I promise, SDG-2 will carry APRS equipment (I just need to
> > find a very light tracker and a GPS that doesn't eat
> > batteries)!
>
> You might try what we plan on for our ocean buoys.  That is, only power up the GPS once every now and then.  Maybe for a balloon, once every 10 minutes for 2 minutes would assure you got a good fix.  That would reduce the battery load by a factor of 5..
>
> Bob, Wb4APR
>
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