MyWingSpeed_beta

MyWingSpeed is an interactive tool to experimentally evaluate a (powered)paraglider wing air speed from phone GPS data. To perform as accurately as possible, several GPS measurements are collected while traveling at different headings. Therefore wind speed, wind direction and air speed are estimated. Several hypothesis are made to have the algorithm performs correctly:
• wind speed is constant,
• wind direction is constant
• wing speed is constant
• heading changes over time

Typical usage:
The pilot is flying at a level flight, with enough ground clearance to guarantee his security and air mass stability. As soon as the application is opened, it starts collecting GPS heading and ground speed measurements and displays them on the screen as magenta dots. If GPS is working well, the data should be updated every second. Once ready to perform a true measurement, the pilot clears data history with the upright reset button. With a light weight-shift, the pilot induces a slow turn so the application can take measurement at a range of headings. As the application gathers data, the estimate of wind speed, wind direction and air speed converges and stabilizes. In practical case, it is not necessary to cover a full turn.

On the graphic display, data related to ground speed are displayed with magenta color, wind data with cyan and air speed with yellow. A good estimate can be visually confirmed if magenta dots are gathered close to the yellow circle along an arc that matches the bearings range covered during the turn. The yellow circle (whose radius is the air speed estimate) and the blue segment (wind estimate) should appear steady on the screen. Then, the estimated air speed can be read on the yellow label at the bottom right.

Enjoy the app and Fly safe!