Terrain Following

Terrain following allows your aircraft to maintain a constant distance above ground level for any waypoints that have been created when planning your mission. Terrain data will be uploaded to the Pixhawk automatically from the ground station during flight planning and stored to the autopilots microSD card.

There are two different sources for terrain data:

SRTM

  • Loaded by default from Mission Planner
  • You can read more about SRTM data here.

Custom GeoTiff

  • You can add your data to the folder in C:\Users\USER\Documents\Mission Planner for Event38\srtm\
  • This data will only be as accurate as the data set that you provided. It should be double checked if it has been converted to a different CRS.

When the autopilot has finished loading the terrain data you should see ter_pend in the status tab of the flight data screen read 0 and the current terrain altitude in meters showing up in ter_alt. The ter_pend value is the number of terrain blocks that the autopilot is waiting to load from the ground station.

We recommend checking your GeoTiff SRTM data from your location with the ter_alt value in the status tab to ensure the data was loaded correctly

Terrain following only looks ahead to the next waypoint

While the E384 has a climb rate of 3.5 m/s you will still need to give it enough time to gain altitude in between waypoints. This could get tricky around turns so it’s smart to check the elevation around turns after planning a mission. Planning a mission at 100+ meters should inherently avoid this problem, with the exception being if there is a cliff.