I have SkyDemon 3.4.1.0 on a PC running XP and SkyDemon Mobile 3.4.0. During my last two weekly flights the SD Mobile Flight Log kept stopping and then starting again. When in SkyDemon Plan Analysis mode the route flown is broken into several segments and is also shown as discrete entities in the Mobile Flight Statistics window. The SD Mobile continued to work correctly apart from the logging function.

The logging function will only stop logging if it thinks you have stopped (helicopter etc), or if you lose your GPS signal for a good amount of time (from memory, at least 30 seconds). One of those will have happened.

Stopping, i.e., ground speed near zero, is not a good indication of when to atop logging in a lot of aircraft. Rotorcraft (helicopters and gyroplanes) can easily have GS near zero during a flight. How about GS=0 and height above ground less than, say, 100 ft?

Or there could be a pop up asking me if I want to stop logging.

-- Chris.

Minor point: I've found that the Tesco Hudl 2 can lose GPS occasionally if it's poorly positioned.  I'd suggest 5 minutes loss of signal rather than 30 seconds.  After all, few flights have less than 5 minutes between them (and when they do, one probably wants to record them as one flight). 

Stopping is defined as groundspeed being below a certainly threshold (around 10 knots) for a minimum period of time (at least 10 seconds). All values from memory. It works well and I don't think there is cause to revisit the algorithm at this point, even if it's not perfect.

The other option is to start logging manually. If you do that, SkyDemon won't stop the log automatically.

I use a Cessna 152 fixed wing aircraft and it has only happened the last twice I have flown. They were 2nd and 9th September 2015. I normally fly each week and have used the SkyDemon equipment for a number of years without knowingly losing the GPS signal.

Ah! That explains why I frequently get "broken" logs when doing aerobatics - I'd always assumed it was because I'd shielded the GPS antenna, but extended vertical manoeuvres would fool the algorithm. Could the "groundspeed zero" test be combined with a "within a few metres of the ground" to prevent false stops?



That's also useful to know - I didn't realise that manual-start would prevent auto-stop. Thanks Tim!