GPS-Anwendungen in der Sportwissenschaft: Entwicklung eines Messverfahrens für das Skispringen

Carrier phase based GPS applications with centimeter accuracy have become more popular over the last years, not only in surveying. First investigations are accomplished in sports sciences as well. However, most geodetic GPS equipment is too large and too heavy for attaching it at the athletes body. Using the potential of miniaturized electronics, a special GPS receiver for ski jumping was developed. The hardware could be integrated completely into a common jumping helmet. Striving to an ideal measurement system with no influence on the athlete activities only little adverse effects remain on the athletes using the GPS-helmet. The topography of jumping hills results in a more or less shadowing of the GPS satellite signals. Not all jumping hills are applicable for GPS measurements. Measurement campaigns need to be well planned considering satellite constellation issues. Centimeter accuracy requires successful integer ambiguity fixing. Common algorithms assume uninterrupted signal reception over a sufficient long time. But the 10 –20 seconds for an attempt, take-off, flight and landing are not long enough. Thus a laser light barrier array was developed. It determines position and time of the GPS-helmet during athletes take-off from the ramp. This information enables the ambiguity fixing and enhances accuracy and reliability of the solution, even for short GPS measurement segments. The system was successfully tested during some training sessions of german ski jumpers. It was shown which informations can be derived from positions and velocities for several phases of a jump.