Comparison of wake-vortex parameters measured by 2 #mu#m pulsed and 10 #mu#m cw lidars

Field trials carried out at Tarbes airfield in the summer 2002 offered the unique possibility to compare the results of simultaneous wake-vortex measurements by the 2 #mu#m pulsed doppler lidar from DLR and the 10 #mu#m cw doppler lidars from ONERA and QuinetiQ. Good agreement could be found for both the vortex-core position and the vortex circulation. Based on this, the accuracy of pulsed lidar measurements has been estimated to be 4.5 m in vertical and 6.5 m in horizontal direction for the core position and to 13 m"2/s for the vortex circulation. This accuracy and the long-range capability of the pulsed lidar allows precise measurements over long periods from the moment of wake generation to a progressed state of vortex decay. Moreover, the influence of different atmospheric turbulence conditions and aircraft configurations on the vortex trajectories and circulation can be analysed. This has been demonstrated under conditions of weak to moderate levels of turbulence. (orig.)Available from TIB Hannover: RR 6341(194) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman