Learn how and when to use terrain following.
Terrain following allows WingtraOne to adjust the flight altitude for every sweep to achieve a consistent GSD. More specifically, the flight altitude of the individual sweep is defined by the highest terrain point of the sweep. The desired GSD or altitude above ground can be specified as usual. Since the flight height cannot be adjusted along the same flight line, to take advantage of the terrain following feature, you need to fly following the contour lines, which run parallel to a slope or a mountainside.
To achieve terrain following, WingtraPilot uses elevation data of the SRTM database with a spatial resolution of 30m. The elevation data can either be fetched online when planning the mission or cached prior to planning (see Download maps for offline use). Use of the SRTM elevation data needs to be enabled when starting WingtraPilot for the first time or later on by clicking the respective option in the WingtraPilot Settings menu. Alternatively, custom elevation data can be imported and used.
Please be aware that the SRTM elevation data is subject to uncertainty and does not account for vegetation, buildings or other objects.
Note: the SRTM elevation data is only available between 60° and -55° latitude. In higher latitudes terrain following can be enabled only when custom elevation data are available. If custom elevation data is not available, to maintain a uniform GSD in these areas, break the flight plan into multiple areas and use the Ground elevation offset feature.
Terrain following can be enabled as a flight parameter. For every area, you can define whether terrain following should be enabled or not. So for flights consisting of multiple areas, terrain following does not need to be enabled for all the individual areas.
Terrain following is enabled by default as it ensures best data quality (uniform GSD and overlaps as set in planning) and makes your flight safer. However, you need to pay extra care in certain situations, e.g. in mines where terrain changes substantially over time, or in cases of steep terrain (slope > 100 percent or 45 degrees).
The altitude graph on the bottom allows you to check the flight height in relation to the available terrain data.