A GPS/GNSS Utilisation Risk Model Facilitates GNSS Applications Development and Operation

The paper presents a methodology for assessing the risk that GPS/GNSS Positioning, Navigation and Timing (PNT) performance will fail to meet the quality-of-service requirements of a particular GNSS-based application. The proposed Probability of Occurrence (PoO) model is based on the statistical analysis of long-term positioning estimation errors and is expressed as a complementary cumulative distribution function. For a predefined application-specific positioning accuracy requirement, the model provides the probability that the GNSS positioning error will exceed the required threshold. The methodology is demonstrated using long-term raw GPS pseudorange observations from IGS reference stations and position estimates obtained with a single-frequency commercial-grade GNSS receiver simulated in the RTKLIB/RTKPOST environment.