GNSS simulation for the International Civil Aviation Organisation (ICAO)

At the second meeting of the ICAO GNSSP (International Civil Aviation Organisation Global Navigation Satellite Systems Panel), in November 1995, the UK panel member presented two papers describing the results of efforts in the development of a GNSS computer model. This model is capable of performing the statistical analyses required to evaluate the effect on receiver performance and on air traffic service provision of variations in satellite geometry and other parameters. The information has since been discussed at working group (WG) level for consideration in respect of the development of a standard model. This paper reports some of the ICAO activities in this field, drawing on information from several GNSSP and WG meetings, and noting other ICAO requirements from AWOP (the All Weather Operations Panel) to aid in setting standards and assessing feasibility for precision approach using GNSS. It is believed that the form of simulation in use in the UK today, with clearly stated assumptions, control of the detailed technical specifications, and operator selection of simulation parameters will help the ICAO member sovereign states to better understand and accept international usage of GNSS. Some of the benefits of simulation are highlighted using the example of a particular requirement in the UK. Activities to establish the feasibility of DGPS guidance for off-shore helicopter operations in the North Sea age currently under way, and include a significant simulation element which is described in this paper.