GPS World, October 2009

ON THE EDGE GNSS Applications Elite Sensor Training Competitive alpine skiers win or lose races by fractions of a second Research has explored GNSS potential to provide position information to skiers and instructors during training However to date the size weight autonomy accuracy and availability performance have posed major obstacles to use The Sensor for the Training of Elite Athletes STEALTH overcomes these limitations to provide a racing edge for Canadian alpine ski teams By Gérard Lachapelle Aiden Morrison Richard Ong and Gerald Cole A top secret program launched in 2006 by Canadian sports authorities enlisted the University of Calgarys Positioning Navigation and Wireless Location PLAN Group of the Schulich School of Engineering to develop an ultra precise ultralight GNSS based device that would meet the requirements of the Canadian Alpine Ski Team CAST to enhance its training leading to the Vancouver 2010 Olympics The targeted specifications for the system were set to allow it to detect relevant differences in line selection between elitelevel skiers for the downhill super giant slalom and giant slalom disciplines and to operate in ambient conditions below 20 degrees Celsius with the potential for moisture For safety reasons the system had to have a negligible influence on the skiers at speeds in excess of 120 kilometers hour A key desired specification called for an accuracy better than 20 centimeters in position and 1 millisecond in timing sampling at a minimum of 20 Hz using a wearable device that would not exceed 500 grams and would have an autonomy of at least 4 hours Starting Gate Development and testing during winter 2006 07 led to a prototype system undergoing successfully testing in April 2007 by the ski team Subsequent to the excellent prototype performance results a second generation system of the wearable equipment was designed for use by CAST Th ese systems known individually as Sensor for the Training of Elite Athletes STEALTH were adopted by CAST starting in fall 2007 and have been successfully and continuously used since both in the original capacity of athlete training and in an expanded role where the systems strengths are leveraged for the performance based evaluation of ski equipment The STEALTH wearable hardware size and capabilities make it extremely compact lightweight and easy to maintain ideal for extended fi eld use and in situations where the user must have total freedom of movement With outer dimensions of only 37 by 78 by 129 centimeters and a mass of less than 280 grams the unit is light enough to be hardly noticeable by the user and small enough to be carried without aff ecting natural range of motion or burdening the athlete with external components Styles For The Slope Th e belt borne component is shown in the opening GPS World October 2009 www gpsworld com 28