Tests of 2-D LOMOPLAN on field data

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

Some field-data examples are in Figures  and . These results are not surprising. A dominant local plane is removed, and noise or the second-from-strongest local plane is left. 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  on paper (which has a lesser dynamic range than video), I recolored the white residual with a short triangle filter on the time axis.

 

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Figure 6 Data section from the Gulf of Mexico (left) and after LOMOPLAN (right) Press button for movie.

The residual in Figure  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.

 

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Figure 7 Portion of Yilmaz and Cumro data set 27 (left) and after LOMOPLAN (right). Press button for movie.