fox128 - 5/20/2023 19:16
If it was gps drift it should be similar both ways[/QUOTE

The best way to tell them apart is it's GPS drift when the difference is between the current swath, and any swath made before the drift occurred. This occurs in pairs. If you continue operating, when the drift goes away, there will then again be a discrepancy between the present, non-drifted position, and any coverage mapped while the GPS was drifted.

An offset issue shows up in swaths in opposite directions. The best way to check for it is down and back passes on AB straight lines. As long as swaths continue in alternating directions, it will show up as a repeating pattern. One swath junction will be x inches too close, the next will be x inches too wide, and it will continue to alternate.

Offset related issues are adjustable just by changing settings. GPS drift issues can either be tolerated, or you can upgrade to better differential correction sources.