Monday, 10 February 2003
Total wind—a new approach for airport wind field analysis
Airport efficiency has become more and more important as both aircraft traffic has increased and financial environment for both airlines and airports has become more competitive. Maintaining high level of safety while increasing efficiency will be essential for future airport operations. Vaisala has introduced a new approach for LLWAS systems – fully integration with airport’s automatic weather observation (AWOS) application. In order to achieve that, we have developed a modular, truly distributed computing architecture called ROA (Remote Object Architecture). In addition to full LAN transparency, ROA offers full hot-stand-by capability that is essential for airport operations. To fully understand the reliability of LLWAS system, effects of various error sources were studied. To ensure the high quality output of phase III LLWAS system, wind measurements have to be equally reliable and error free. Main error sources for airport wind measurements are:  Terrain inducted wind patterns.  Wind anomalies caused by man-made structures or trees.  Aircraft jet wash and wake vortex.  Wind sensor malfunctions.  Communication errors between wind measurement sites and main computer. Simulations show (Fig. 1.) that both wind speed underestimate and errors induced by terrain and aircrafts as random variation, can cause significant error in LLWAS warnings. However, simulations show also that wind speed underestimate even in one sensor results bigger impact on aircraft safety than random errors. That is mainly because LLWAS Phase III data filtering removes most of random variation, can not detect biases in data stream. The next logical step from LLWAS application is to try to understand the wind field at airport and its immediate vicinity. Changes in wind directions result in runway reconfiguration and wake vortex advection causes landing and take-off separations to be increased. Terrain induced wind shear patterns are a major problem in some airports, especially in areas where mountains are close to the airport. Our future goal is to define the operation-critical features of an operational wind field and three-dimensional wind shear system as well as assess feasibility of developing such a system in view of existing meteorological observing and modeling capabilities. A system that could integrate multiple input types like anemometer, wind profiler, doppler radar, mesoscale model etc. could give an airport user better understanding of wind conditions affecting both airport efficiency and aviation safety.