Seismic data is used to visualize the groundEarth's sub surface. This is achieved by measuring travel times of reflections from pressure waves propagating through the ground. Seismic data and interpretations of seismic data will therefore often have z values in travel time, not depth. In order to get a depth value for the travel time values, we need to do a depth conversion. A depth conversion combines the velocity of the pressure wave with the travel time to get a depth value.
...
A velocity model is stored as an item in your Project. I represents the seismic velocities in an area, and is used as input to the "Velocity Model Depth Convert" command. In order to create a velocity model, set a "Velocity models" schema on a generic folder, and run the command "Generate Velocity model". In order to see or edit the parameters of a velocity model, right click the velocity model item in the project and select "View/Edit".
...
When going from top to bottom, the layer velocity model will initially use the water velocity as interval velocity until it meets the top horizon. From the top horizon, it will use the top horizon velocity as interval velocity until it meets the next horizon, and so on.
During depth conversion, the interval velocities are used to calculate an average velocity.
RMS velocity (Stacing velocities)
...
Note that the Search radius should be big enough so that all points where you need a velocity will have RMS points within the search radius. However if the search radius is set too big, the velocity computation for a point will include too many RMS points, and the calculation will may be slow. The recommended radius will vary depending depend on the density of the RMS velocity dataset.
...
The velocity model will clamp the last valid velocity below the bottom velocity in the velocity cube as velocity below . It will also clamp the first valid value above the first valid value of the cube.
Depth Conversion
...