LIDAR for air-data calibration
Flight Tests with LIDAR on Piaggio P.180 performed successfully
ONERA Lidar flight tests conducted during the AIM² project took place from the 7th to the 26th of February 2014 on the Piaggio site in Genova (I). The aim of these flight tests is to demonstrate that the measurement of the static error, the angle of sideslip as well as the angle of attack with a LIDAR can increase the quality of flight tests data and simplify aircraft certification procedures.
The figure shows the ONERA Lidar implementation on board the P.180 experimental aircraft. The system includes the driving unit which is composed of four single components (Laser, optical/ electrical detector, power supply and PC) compatible with aeronautic constrains located in one rack provided by Piaggio.
The Sensor head which is precisely positioned with respect to the aircraft reference frame is integrated on another rack. The four lidar beams are sent through an optical grade glass window to probe the atmosphere and measure the true air speed (see figure in the upper right corner).Three flights of about one hour have been performed during the test campaign. The diagrams in the figures illustrate the acquired raw data during a pull up manoeuvre and a preliminary processing.
The upper diagram shows the raw spectra of the four lidar axis. The lower diagram shows the three components of the aircraft true air speed after processing of the Doppler frequencies extracted from the spectra.
Beyond the steady flight sequence (corresponding to samples 0 to 150), the pilot pulled the stick up to a load factor of 2g (samples 150 to 220). We can see the along path speed component Vx decreases and vertical speed component Vz increases.