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Unmanned Aerial Vehicles (UAVs) provide the ability to perform a variety of experimental tests of systems and unproven research technologies, including new autopilot systems and obstacle avoidance capabilities, without risking the lives of human pilots. This paper describes the activities of design, optimization, and flight operations of a UAV conceived at Clarkson University (USA) and equipped to perform wind speed measurements to support wind farmsite planning. The UAV design has been assisted and validated by the use of an automatic virtual environment for the assisted design of civil UAVs. This tool can be used as a “computing machine” for civil UAVs. The operator inputs the mission profile and other generic parameters and data about performance, aerodynamics, and weight breakdown are extracted. A mathematical model of the UAV for flight simulation and its dynamic computations, along with automatic drawing is also produced.

The modal parameters of an aircraft structure are currently estimated from ground vibration tests (GVT). These tests are carried out on ground in order to estimate the frequency response functions first and then the modal parameters. Such estimates require one or more shakers to excite the structure together with simultaneous measurements of both the input and the output signals. Recent developments in operational modal analysis allowed such modal identification from the measurements of the output responses only, provided that the unmeasurable excitation is practically a white noise stochastic input in the frequency range of interest and is randomly exciting the different parts of the structure. In this paper the effects of the different test setup on the modal parameter estimates will be presented. Both input-output based experimental modal analysis and operational modal analysis are performed on an Unmanned Aerial Vehicle, the Clarkson University Golden Eagle.