A fast and efficient integrity computation for non-precision approach performance assessment

作者：Milner Carl D^*; Ochieng Washington Yotto

来源：GPS Solutions, 2010, 14(2): 193-205.

DOI：10.1007/s10291-009-0134-3

• GPS integrity
• Non-precision approach
• Performance assessment

The level of safety to be expected from global positioning system (GPS) must be known in order to use it to support safety critical operations such as air navigation. This is captured by the navigation performance parameter of integrity which includes the ability of the navigation system to deliver a warning to the user in the event of a significant failure and within a specified time-to-alert. Given the high percentile requirement associated with integrity, assessment of expected system performance both in the nominal case and during failure events, requires the application of analytical techniques. This paper identifies the weaknesses of the current methods for assessing the level of performance to be expected of GPS for non-precision approaches and proposes ways to address them including a novel application of a mathematical integration technique that greatly reduces the computational load associated with integrity performance calculations. Results based on computation times show that the new method reduces computational load by a factor of 500 with a high accuracy and associated high level of confidence. It is shown that in some cases, the technique presented is able to improve GPS RAIM availability beyond the gains achieved by measurement weighting.

• 出版日期2010-3