I have been using Pocket Eartg with a DUAL xgps160 GPS.
I fly from Vancouver to Sydney regularly and use Pocket earth on my ipad to track the flight. Every time I do this route, I end up with an additional track overlay that goes around the world at roughly the equator. Just wondering if you have any idea what causes this??. It seems to happen crossing the International date line. It does not show this in the GPS log.