Altitude helpers, also known as terrain following, assist in converting flight paths from Above Ground Level to Mean Sea Level or the drone's Home referential.
In areas with significant slopes, programming the drone to maintain a constant elevation above ground level is crucial for staying below the maximum authorized altitude and above the minimum safety altitude, ensuring avoidance of artificial or natural ground obstacles.
The altitude helper service is available as an API. Further details are provided below.
When executing Beyond Visual Line of Sight (BVLOS) missions, drones must adjust their altitude Above Ground Level (AGL) to remain below the maximum regulatory authorized altitude and above the minimum safety altitude, avoiding artificial or natural ground obstacles. The challenge lies in the drone's reference system, which is either based on a barometer calibrated at the departure point or on GNSS combined with Real-Time Kinematic (RTK) positioning, providing altitude Above Mean Sea Level (AMSL). The missing element is ground elevation. Stratomaps' Altitude Helpers, or terrain following, address this by converting AGL flight paths into AMSL or into the drone's Home referential. For this purpose, we process high-resolution and precise Digital Elevation Model (DEM) data for specific mission zones.
The Elevation API includes four endpoints to:
Provide elevation data for any ground location
Associate elevation with each location in a KML or GPX file
Transform AGL paths into the drone’s home referential
Transform AGL paths into MSL
Technical API details can be found in the developers' zone.
The altitude helper API is provided as a service. However, it is not a substitute for obtaining flight authorization from relevant regulatory authorities.