Thermal Finder is a new technology to enhance probability of finding thermals in areas where no visible thermal clues are available. Sierra SkyWare has a Pending Patent for this technology.
A set of flight data logs from past flights performed over a given area is analyzed, and a list of places on the ground that have generated thermals is produced. To find a location on the ground that has generated a given thermal, WinPilot takes in the consideration altitude above the ground where the thermal was found, wind speed and direction, and the strength of the thermal. Then, it projects the location where the thermal was found to the ground, given the above variables. Note that this is very different from simply marking the gps position where the thermal was found in the air. Because of the drift that the wind is causing, simply marking the air position of a thermal does not accurately point to the ground source that generated that thermal, and therefore, it is of limited or no use in subsequent flights, where the wind speed, direction, and glider’s altitude are different.

Our Thermal Finder technology attempts to accurately locate the spot on the ground that has generated a given thermal, and then in flight, given the wind speed, direction and the current altitude above the ground of the glider, it starts a thermal at the ground source and projects it upwards, applying the wind drift all the way to the altitude of the glider.

Thermal Finder technology can be useful for flying in mountains, hilly terrain, or other terrain that has many unique features. It is less useful for flying over homogenous areas, where thermals are generated more randomly. Every pilot has his favorite ‘house thermals’ that usually are close by to the home airport, and are known to generate thermals more reliably than other places. Thermal Finder extends this concept to cover areas away from home, where cross-country flights are taking place.

WinPilot XP analyzing set of flight logs to find places on the ground that have generated each thermal.

Gray lines show wind drift between thermal source on the ground (shown here with a blue cross-hair), and location in the air where the thermal was found. Also shown (and stored in the Thermal Database) are: angle from where the Sun was shining (shown with a red line), and wind speed and direction at the time thermal was generated (shown with a black line).

In flight, the projected positions of thermals are shown on the map. WinPilot takes each ground source, assumes that it generates a thermal, and adjusts the position of the thermal based on the current wind and altitude of the glider above ground. The pilot can specify that only thermals generated when the Sun was shining from the same angle as currently, and the wind was blowing from the same direction as currently are shown.