Create Constant Horizon is found in the Map View, under the Operations tab (along with other horizon operations).

1. Open the Map View.
2. Expand the left panel and open the Operations tab.
3. At Operation, select Create Constant Horizon.

1. Enter a Value for the horizon.
2. Select the Vertical dimension to use.
3. For Area, select a polygon/probe to constrain the operation.
   • To create a probe or a polygon, see Creating a Polygon in Map View or Creating a Probe.
4. Enter the Spacing (m) (grid cell size, or increment) for the horizon.
5. Select the Survey touse.
   • Choose <<X/Y>> for a regularly spaced grid without a survey.
6. Extents are calculated from the selected area, survey and spacing.
   • If a 3D survey is selected, the spacing is converted to an IL and CL step size.
7. Optionally, select a Gather dimension and enter the Gather Extents (Use the format: Min - Max [Increment]).
   • Offset (m) or (ft)
   • Frequency (Hz)
   • Channel
   • Semblance
   • Realization
   • Angle (°)
   • Rotation Angle (°)
   • Bin
   • Indexed Bin
8. Select Fault Polygon to prevent the horizon from being created inside the selected fault polygon (see Using Fault Polygons).
9. Click Calculate to start the operation.

 After running the operation:

• At Class: Choose the Display Class for the results
• Use min and max from class settings (checked)
  • Use amplitude ranges from the class. Update the range in the display class.
• Use min and max from class settings (not checked)
  • Set specific a min and max value for this result.
  • Click Adjust to set the Min and Max from the extracted amplitude.
• Click Discard to cancel this calculation and delete the results.
• Click Create to create a new horizon containing the extracted values.
• Click Add property to store the result as a horizon property.