This is the acceptable amount of change in the trace to trace separation distance. It is expressed in meters or feet, depending on the unit of your data. The default value of 2.5 is usually appropriate.
If the first two traces in your 3D dataset are separated by 50 m, then a separation of more than 52.5 m or less than 47.5 m in other adjacent traces, would cause WinPICS to report an error. If you are working in feet, you may need to increase this number to 5 or even 10.
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