Stratomaps’ terrain following service, converts flight paths from Above Ground Level (AGL) to Above Mean Sea Level (AMSL) or above the drone's Global Navigation Satellite System (GNSS) referential.
In areas with significant slopes, programming the drone to maintain a constant height 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. Beyond the aspect of safety, maintaining a constant altitude AGL is critical for the success of the data collection process.
Drones engaged in survey missions, such as those involving photogrammetry or Light Detection And Ranging (LiDAR), must maintain a steady height above ground. This consistency is crucial for capturing accurate and reliable data. The challenge for operators and pilots often lies in the default resolution and precision of the Digital Elevation Model (DEM) they have access to for the operation zone. In most cases, the default accessible DEM is usually 1-arc second (1 elevation every 30 meters).
Local higher resolution, precision data sources usually exist, depending on the geography, but not necessarily in the proper horizontal and vertical Coordinate Reference System. In most cases, missions requiring high horizontal and vertical accuracy are relying on the drone’s GNSS combined with Real-Time Kinematic (RTK) positioning, providing altitude above the Ellipsoid.
Doing manual conversion of more accurate local DEM is always possible but requires some Geographic Information System (GIS) expertise and is time consuming for pilots who want to focus on their mission. stratomaps’ facilitate this process by providing for the operation zone interactive 3D maps visualization with tools to :
Draw a Keyhole Markup Language (KML) path manually, fix height AGL and export the KML with a higher resolution ready for import into the drone's ground control system.
Upload a KML path with vertical dimension provided AGL and export the KML with a higher resolution ready for import into the drone's ground control system.
Draw a specific zone to generate a DEM/DSM (Digital Surface Model), ready for import into the drone's ground control system.
For deeper integration into a custom application, Terrain Following can also be integrated using the stratomaps’ API.
The terrain following product is not a substitute for obtaining flight authorization from relevant regulatory authorities.