Application of the Global Positioning System in Determination of Vehicular Acceleration

Abstract

Aircraft landing and takeoff performance monitoring is an area of research aimed at improving the information available to the pilot for decision making during takeoff or landing. A system capable of instantaneously determining the stopping distance of an aircraft could form an integral component of a monitoring system. Particularly difficult to quantify is the frictional coefficient between the runway and the aircraft tires, should such a measurement be necessary. In secluded far-northern regions, where a monitoring system would be particularly useful given adverse weather, few airports are equipped to attempt frictional measurements. In such instances a monitoring system would need to be totally self-contained and able to determine aircraft ground speed, acceleration, and position relative to the end of the runway. Prediction of the aircraft's location at rest is then possible. It is proposed that the Global Positioning System (GPS) be used to determine aircraft acceleration, ground speed, and position relative to the end of the runway. A practical evaluation of the feasibility of this proposal showed clear superiority of a GPS-derived acceleration over a more traditional method employing accelerometers. Advantages of the GPS-derived measurement include a modest noise level, insusceptibility to gravity and temperature-influenced variations, and far simplified mounting criteria.