It looks like you're new here. If you want to get involved, click one of these buttons!
Can someone tell if you have similar issues with ios + xgps160? I use this setup maybe for 5-6 years, but last few years I get jerky lines and inadequate gps readings at the same spot on the track (Rustavi, Georgia). Last firmware update for xgps did not help... It's worth mentioning that my buddy just got his new xgps160 and it works smooth like mine did when it was new.
Here are some screenshots with glitches. I use it on car and bike, and always mount solid with double sided tape.
Last screenshot applies to linked video, you can see how readings jump inadequately at the same spot staring at left U turn.