SkyDemon Forums

Unexpected GPS data encountered

http://forums.skydemon.aero/Topic27952.aspx

By ge89 - 6/9/2022 8:54:59 PM

I struggle with the same problem. Since it's a rental plane, I can only report the problem to the flying club and hope they would contact the manufacturer (which they won't just because of a single complaint).

While I understand and support the policy of rejecting bad data, I wonder if there is not a better way to handle it in Skydemon. As already pointed out by others, ending the navigation mode and thus forcing the user to deal with a technical issue in flight is not optimal.

When losing connection to the traffic receiver a manual fallback mechanism is provided. Wouldn't it be possible to use a similar mechanism in case of bad data? SkyDemon shuts down the communication with the device, displays a banner indicating that bad data has been received and therefore no location/traffic information is available. By acknowledging the banner, SkyDemon stays in navigation mode and temporarily reverts to using the device’s Location Services (if available). SkyDemon reconnects to the traffic receiver in the background and as soon as valid data is received, SkyDemon will automatically switch back. When the user intentionally ends the navigation mode (e.g. after the flight), a complete error message can be displayed.

Finally, this would still follow the reasonable policy of rejecting bad data (not tolerating/ignoring corruption) and the user would be informed (multiple times) of a possibly erroneous behavior of the traffic receiver. At the same time, the user would not directly be burdened to deal with it in flight, can keep navigating, logging the flight and no timers would be reset.
By Florian - 3/4/2019 6:17:49 PM

Hi,

I try to use SD together with TRX-1500 Flarm and Airconnect. On almost every flight I get an "Unexpected GPS data encountered" messages popup. It always complains about PFLAA and PFLAU sentences which as far as I can tell are position reports Flarm receives.

Unfortunately it is quite annoying that SD seems to open up 3 to 10 popups (the amount seems random...) about the same sentence and simultaneously kicks itself out of navigation mode. In my opinion this behavior does not contribute to flight safety since you have to fiddle around to much to get SD back and running! And as a side affect, the flight log is broken which means that if I used one of the time tracking functions, they won't spit out a usable result after the flight.

I noticed that behavior on all SD versions since I installed my Flarm in summer last year until today. I am running SD under Android 4.2.2 on a Samsung Galaxy Tab 2.

I also noticed that the more aircraft are in the vicinity which likely have Flarm, the more quickly the  popups appear. So the is a linear trend of Flarms flying around and SD complaining about broken sentences.

SD-Team, can you please change the way SD handles data sentences it deems to be broken in a way that allows the pilot to continue his/her duty of  navigating and to observing traffic. If you still want to track broken sentences, I suggest write them down into a log file for example. In my opinion, it is better for flight safety, to just quietly drop a sentence here and there than waiting for the user to close multiple popups and restart navigation mode.

If there is anything I can do to help you in fixing this issue, please let me know!


Florian