I ordered a UBLOX NEO M8U GPS unit from Drotek in France. The GPS has dead reckoning built in, and will continue to provide position information even with no satellite reception.
If I'm using a PixHawk, and this GPS unit, what will the PixHawk do when it receives the "NO FIX" message? Will it continue to use the information from the GPS? Or will it ignore the GPS signal at that point?
Of course, I would prefer that it continue to use the GPS information, and flag me that it was using dead reckoning as a means of navigation.