Identification of obstacles

Satellite obstacle identification

In area with no public LiDAR/Elevation modelsavailable, and if an individual data gathering is out of the airports price range, Ascend offers an alternative using the NextMap 5 elevation model, or WorldDEM elevation model generated from TerraSAR-X/Tandem-X data.

The Ascend Obstacle Management solution uses satellite elevation data to determine the terrain elevation. The main use of satellite elevation data in the Obstacle Management Solution, is as a terrain elevation model. This can be used to handle”allowed height” requests to the airport. Furthermore, with the terrain elevation model in the system the Ascend Obstacle field app enables the airport personnel to easy gathering of obstacle height with simple field equipment.

Obstacle analysis based on satellite generated elevation data, is not a complete obstacle analysis, as the resolution and the acquisition date of the data is not sufficient to find all obstacles from the data alone. It is recommended to use this type of obstacle analysis as a starting point for a field measurement of the obstacles in the airport area.

NextMap 5 and WorldDEM

NextMap 5 is available in most areas within the +/-60 latitude. NextMap 5 has a vertical accuracy of 1,65m LE90 in most areas. This can vary in some areas and must be verified in these cases. WorldDEM is available worldwide, but the resolution is lower than Next5 and the vertical accuracy is lower.

LiDAR obstacle identification

For a complete obstacle analysis, Ascend use LiDAR data. LiDAR is used to be certain of the detection of all obstacles within the relevant area. LiDAR data, with a minimum 5-year life cycle, is recommended for ADQ compliance within the Annex 14 surfaces of the Airport. Area 2 LiDAR data is also recommended for ADQ compliance.

For airports in areas without public LiDAR data, Ascend can originate the data. The data is gathered with a LiDAR density of minimum 10 samples/m2. This enables us to find obstacles in the data, including thin objects as wireframe masts and light poles. Currently LiDAR acquisition is available for Europe and North American airports.

Manual obstacle identification

Using the limitation surface management solution, airports can manually inspect the surroundings with the ability to accurately determine, if an obstacle penetrates the protective surfaces. We recommend using a mobile laser measurement device like the Nikon Forestry pro for manual observations.


Protective surfaces must be monitored for obstacles. We can help you identify the best data available in your area or originate new data. The aeronautical data requirements can vary depending on local regulations. Contact us for more.

Public data

In some countries, public LiDAR data, that meet the ADQ requirements, are available for free or a fraction of the price it costs to gather individually for the airport. In the case that public LiDAR data is available for the Airport, Ascend will evaluate the data quality, with focus on vertical and horizontal accuracy, sample density and a potential life cycle of renewal of data.

Obstacle identification layers

Based on the LiDAR of satellite data Asend develops Obstacle Identification Layers. The layers are visualized as red clusters in the map. By holding your cursor over the cluster, you can see the penetration. The layers are divided in to 3 groups:

  • Obstacle Limitation Surfaces
  • Operational Surfaces
  • AOC type A surfaces