Using this technique allows the researchers to study the flight mechanisms of free-flying birds, which apart from being more informative offers an ethical means of bird flight analysis. Several cameras are mounted on the bird's back or belly and point at the wings, head and tail. The motion measurement unit weighs less than 50g and provides complete 3-dimensional information on the orientation, rotation and acceleration of the Eagle. The research group want to fit their motion measurements to dynamical models of bird flight to allow them to work out how the Eagle's control system functions.
Recent trials in Denmark have proved successful. "We can measure tail spread, pitch angle and bank angle from the onboard video directly", says Taylor. "The plan is to relate these measurable control inputs to the body motion of the bird, which we can quantify using the motion measurement unit."