FIELD DATA TESTS

Although the LOMOPLAN concept was developed for geophysical models, not raw data, initial experience showed that the LOMOPLAN program is very effective for quality testing data.

Some field data examples are in Figures 4 and 5. These results are not surprising. A dominent local plane is removed, leaving noise or the second from strongest local plane. These data sets fit the local plane model so well that subtracting the residual noise from the data made little improvement. These Figures are clearer on a video screen. To facilitate examination of the residual on Figure 4 on paper, I recolored the white residual with a short triangle filter on the time axis.

 

dgulf
Figure 4 Data section from the Gulf of Mexico (left) and after LOMOPLAN (right) Press button for movie.

The residual in Figure 5 is large at the dead trace and wherever the data contains crossing events. Also, closer examination showed that the strong residual trace near 1.1 km offset is apparently slightly time shifted, almost certainly a cable problem, perhaps resulting from a combination of the stepout and a few dead pickups. Overall, the local-plane-residual shows a low frequency water velocity wave seeming to originate from the ship.

 

yc27
Figure 5 Portion of Yilmaz and Cumro data set 27 (left) and after LOMOPLAN (right). Press button for movie.