Simulations for Computer Centerline Approach

Abstract : Position computation for any Microwave Landing System (MLS) Area Navigation (RNAV) approach has an associated accuracy. This accuracy is affected by several error sources: MLS signal source errors, data word granularity in describing MLS ground station siting, and the MLS RNAV coordinate transformation algorithm. The International Civil Aviation Organization (ICAO) signal source errors and allowable degradation, specified in ICAO Annex 10, were used in their simulations. Since the coordinate transformation algorithms are nonlinear, it is necessary to use Monte Carlo simulation techniques to determine the magnitude of position determination accuracy in the presence of MLS signal source errors. This report presents the results of simulations undertaken by the Federal Aviation Administration (FAA) Technical Center to determine the accuracy of the RNAV at the Categories I and II minima, and at 50 feet above ground level for Category III in the presence of the MLS signal source errors and associated allowable error degradation. (kr)