Editing and fundamental corrections-Obvious experimental failures due to humans or machines are flagged for removal from the records.As computers move into the field, more of this work will be done at the dog house. The proper assignment of these geometrical properties is fundamental to all that follows. Database building-The myriad of numbers on field tape must each be uniquely related to shot and receiver positions on the surface of the earth, an elapsed time after the shot that originated the reflection or echo (traveltime), and a reflection point on the subsurface of the earth at any traveltime.However, the steps can be grouped by function so that the basic processing flow can be illustrated as follows:

The number of steps, the order in which they are applied, and the parameters used for each program vary from area to area, from dataset to dataset, and from processor to processor. The processing sequence designed to achieve the interpretable image will likely consist of several individual steps. Figure 2 is the same line of data after processing to illustrate how the field records are turned into an interpretable image. Figure 1 shows a single, unprocessed (raw) field record taken from a line. This simple image, while it contains less data about the subsurface, is readily accessible to the interpreter and has many of the artifacts and errors just listed removed. Through processing, the huge volumes of data taken in the field are reduced to simple images for display on paper or the work station screen.

Treatment of the data to achieve these ends is commonly referred to as seismic data processing. To create an accurate picture of the subsurface, we must remove or at least minimize artifacts in these records related to the surface upon which the survey was performed, artifacts related to the instrumentation and procedure used, and noise in the data obscuring the subsurface image. The seismic data written to tape in the dog house, whether on land or at sea, are not ideal for interpretation.

Basic data processing functions