A low-cost system for measuring horizontal winds from single-engine aircraft

The system is based on a global positioning system (GPS) compass that provides aircraft heading and a ground-referenced velocity, which, when subtracted from the standard true airspeed, provides estimates of the horizontal wind velocity. A series of tests was performed flying "L"-shaped patterns above the boundary layer, where the winds were assumed to be horizontally homogeneous over the area bounded by the flight (approximately 25 km²).

Four headings were flown at each altitude at a constant airspeed. Scaling corrections for both heading and airspeed were found by minimizing the variance in the 1-s wind measurements; an upper limit to the error was then computed by calculating the variance of the corrected wind measurements on each of the four headings. A typical uncertainty found in this manner tends to be less than 0.2 m s⁻¹.