Use Helicopter Landing Zones to identify locations within an elevation model that would be suitable to land a helicopter.

You can also write a script to identify helicopter landing zones using the HelicopterLandingZones task.

This tool generates a classification image showing helicopter landing zones, safety buffers around the landing zones, and nearby flight obstruction hazards. Landing zones are identified by locating large contiguous areas which satisfy minimum requirements for size, slope, surface roughness, and the presence of obstacles. The output image raster contains five classes:

  • Locations unsuitable for landing (black)

  • Acceptable landing zones with slope of 7 degrees or less (light green)

  • Acceptable landing zones with slope between 7 and 15 degrees, which may be used with an advisory (dark green)

  • Safety buffers around the landing zones (yellow)

  • Potential flight obstructions near the landing zones (red)

Reference: U.S. Army, "FM 3-21.38 Pathfinder Operations" (2006).

  1. From the Toolbox, select Mobility > Helicopter Landing Zones. The Helicopter Landing Zones dialog appears.

  2. Select a digital surface model Input Raster and perform optional spatial subsetting and masking, then click OK. Note that Digital terrain models (DTMs) or bare earth models are not appropriate to use with this tool and may produce spurious results, as they do not contain obstructions such as trees and powerlines which this tool seeks to identify.

    Note: You can generate a DSM raster from a lidar point cloud file using the Point Cloud Feature Extraction tool.

  3. Select the Helicopter Type. The helicopter landing zone tool includes several standard categories, based on helicopter size and usage. These categories are:

    • User-Defined: Allows for user input of custom size parameters.

    • Light Observation: Includes helicopters such as the OH-6 Little Bird and the OH-58 Kiowa.

    • Light Utility: Includes helicopters such as the UH-1 Iroquois "Huey", the AH-1 Cobra, and the H-65 Dolphin.

    • Medium Utility: Includes helicopters such as the AH-64 Apache, the UH-60 Blackhawk, and the H-2 Seasprite.

    • Cargo: Includes helicopters such as the CH-47 Chinook, the CH-53 Sea Stallion, and the H-3 Sea King.

    • Slingload: For helicopter operations using a slingload.

    • Slingload Long-line: For helicopter operations using a long-line slingload.

    • Slingload with NVGs: For helicopter operations using a slingload while wearing night vision goggles (NVGs).

  4. If Helicopter Type is set to User-Defined, specify the Helicopter Size and Landing Zone Size in meters. The safety buffer is determined by the difference between the helicopter size and the landing zone size.

  5. Select the Landing Gear used by the helicopter, either Skids or Wheels. Wheeled landing gear allows a helicopter to land on a steeper slope (15 degrees) than with skids (7 degrees).

  6. Select the Operating Conditions, either Day (permissive), Day, or Night. The operating conditions influence the minimum allowable height and distance of nearby flight obstructions.

  7. Select whether to Allow Hover. This will allow the helicopter to hover at a specified height above the landing zone and will offset the minimum allowable height and distance of nearby flight obstructions accordingly.

  8. If Allow Hover is set to Yes, specify the Hover Height in meters.

  9. In the Output Raster field, specify an output location and filename for the helicopter landing zone raster.
  10. Enable the Preview check box to see a preview of the settings before you click OK to process the data. The preview is calculated only on the area in the view and uses the resolution level at which you are viewing the image. See Preview for details on the results. To preview a different area in your image, pan and zoom to the area of interest and re-enable the Preview option.
  11. Enable the Display result check box to display the output in the view when processing is complete. Otherwise, if the check box is disabled, the result can be loaded from the Data Manager.

  12. To reuse these task settings in future ENVI sessions, save them to a file. Click the down arrow next to the OK button and select Save Parameter Values, then specify the location and filename to save to. Note that some parameter types, such as rasters, vectors, and ROIs, will not be saved with the file. To apply the saved task settings, click the down arrow and select Restore Parameter Values, then select the file where you previously stored your settings.

  13. To run the process in the background, click the down arrow next to the OK button and select Run Task in the Background. If an ENVI Server has been set up on the network, the Run Task on remote ENVI Server name is also available. The ENVI Server Job Console will show the progress of the job and will provide a link to display the result when processing is complete. See ENVI Servers for more information.

  14. Click OK.

See Also

Mobility Tools