Dynamic soaring of albatrosses over land

Results from in-flight measurements of dynamic soaring of albatrosses over land are pre-sented. Using a new computational method based on L1 phase measurement as well as min-iaturized and low cost GPS logging devices featuring a sufficiently high data sampling rate, it was possible to determine precisely the flight path and the motion quantities of the birds. The recorded data of the flight over land show the characteristic pattern of dynamic soaring that consists of continually repeated cycles comprising a windward climb, an upper curve, a leeward descent and a lower curve. A further point is the mechanism of the energy transfer from the wind to the bird. It is shown that the upper curve of a dynamic soaring cycle is the decisive flight phase of the energy gain.