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Seismic data is used to visualize the Earth'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 a travel time value, 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. 

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To create a new velocity model

  1. Locate or create a folder of type Generic.
  2. Right-click a generic folder with the the folder and click Set Schema. Click Velocity models schemaSelect .
  3. Right click the folder and click Generate Velocity modelModel
  4. Set Adjust the parameters you want to use in your modelmodel parameters.
  5. Click Execute.

A new velocity model i will be created in the folder. 

To view or edit an existing velocity model

  1. Right click the velocity model
  2. Select "View/Edit"

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  1. The model editor dialog will appear

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  1. .
  2. View or edit the model parameters.

Supported velocity models

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Geocap currently supports these types of velocity  models:

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The depth conversion command has options to store the Average average velocity used to do the depth conversion of each point in the result. You may also choose to store the "Instantaneous Velocity". The "Instantaneous Velocity" is computed by looking at the change of average velocity from the velocity model around a point. For seismic lines the the " Instantaneous Velocity" is the interval velocity of a single sample in the seismic. Storing and visualizing these velocities will make you able to quality control the velocity model used for the depth conversion.

If you store velocities when depth converting seismic lines , the velocity values are stored as seismic attributes to the resulting seismic lines. You may visualize the velocities with the regular "Seismic Display" command. Note that storing velocities will make the depth conversion of seismic lines slower. 

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