This diploma thesis examines the influence of wind on civil aviation safety. Author investigates the methods of wind measuring on board of small airplane and identifies the most common individual errors.

An original approach for measuring wind speed and direction by the use ofdrones was proposed and compared to an existing one. The original approach allowed the drone to drift with the wind and use the translatory velocity for input into a non-linear estimator, while the existing approach used a stationary hovering drone and its tilt for input to an estimator. A simulation environment was set up in Simulink and Matlab and validated using outputs from previous researchers performing similar tasks. The first test exposed the two approaches to wind tunnel-like environment with a strictly horizontal wind, while the second test used real wind data collected on-board a meteorological research vessel. Results showed that the original approachperformed better for estimating both direction and speed, but it required a largearea to drift in during operation. / En egen teknik för att mäta vindhastighet och vindrikting med en drönare föreslogs och jämfördes med en befintlig teknik. Det egna sättet tillät drönaren att driva med vinden och använde dess egna hastighet för att estimera vinden, medan den existerande tekniken höll drönarens position konstant och estimerade vinden med hjälp av farkostens lutning. En simuleringsmiljö inrättades i Simulink och Matlab som validerades medhjälp av resultat från tidigare liknande forskning. Det första testet som genomfördes exponerade de två tillvägagångsätten för vindtunnel-liknande förhållanden, medan det andra testet använde verklig vinddata som samlats in ombordett meteorologiskt forskningsfartyg. Resultaten visade att den egna teknikenproducerade noggrannare upskattningar av både vindhastighet och riktning,men krävde betydligt större fritt flygrum.

In the first section of this document, there are described principles of the wind measuring. Anemometers can be divides by physical principles to mechanical (propeller or cup), ultrasonic anemometers and thermoanemometers. This paper is focused to ultrasonic anemometers. In the next part, there are described principles of sound propagation in the atmosphere. There are studies of measurement theory and comparing of different approaches. Completed solutions are presented in patent exploration. Afterwards, there are introduction of market research. Important parameters of ultrasonic anemometers are highlighted. Main aim of work is designing prototype of ultrasonic anemometer. Software, hardware and construct of experimental anemometer were designed. Created anemometer was calibrated in aerodynamics tunnel and results were compared with simulation output.