Dear all,

I am doing this marine magnetic survey at a jetty/ barge, where the seabed is scattered with various dumped materials (proven from side scan sonar mosaic). After producing the QAS grid, I found the anomaly patches show a "survey line-following" trend, which means you could easily tell the survey line orientation etc by only looking at the QAS result. The result is so unreal and I couldn't figure out the main reason causing it. I have made a small assumption to trying to explain it (see picture 7 attached), and tried larger iteration number when producing residual grid.

I have attached the detail processing steps, together with illustrations to make this thing easy and clear for your understanding. If you need more information, please leave your comment and I will update you very soon. I would really appreciate if you could help me to understand this. Thank you in advance.