This is the first window shown when you open Diffract. You here will specify the one-dimensional velocity model and location of any diffractors that you wish to model.
Several aspects of the profile should be set here:
Number of Soundings is the number of traces you wish to see in the Plot Window. Usually you want a subset of the traces you might have recorded in the field.
Trans-Rec. separation is the separation between the transmitter and receiver.
Sounding Spacing is the distance between the individual soundings. The length of the profile is the (Number of Soundings - 1) x Sounding Spacing.
The diffraction patterns are calculated from a one-dimensional velocity structure listed in the model pane in the center of the window. The velocity structure can be adjusted by clicking on the velocity or thickness, layers can be added or deleted using the buttons. Arrivals shown in other plots are selected using the checkboxes. Changes made to the model and waves selected do not effect other windows until you click the Update Times and Plots button.
When Reflections/Diffractions are selected, a second list appears at the bottom of the window containing the location of diffractors.
When the diffractor list is active (highlighted), the buttons become Add Diffractor and Delete Diffractor. A diffractor's ID, horizontal position (X), depth, and relative brightness can be adjusted within the list box.
In both list boxes, tabs and shift-tabs will move from editable cell to cell.
Additional changes occur when line fits are used to adjust the model.