Impact of predicting real-time clock corrections during their outages on precise point positioning
MetadataShow full item record
Real-time precise point positioning (RT-PPP) is a popular positioning method for natural hazard warning systems (NHWS) such as for monitoring tsunami and earthquakes. PPP relays on the use of precise orbits and clock corrections. Hence, the positioning accuracy of RT-PPP will significantly deteriorate when experiencing a discontinuity in receiving these corrections, for instance due to a temporary modem failure. The best available approach in this case would be to use the International Global Navigation Satellite Systems Service ultra-rapid (IGU) orbits and clocks that would result in a low positioning accuracy. In this paper, we present a simplified approach to a method that we recently proposed to bridge outages in the corrections and improve the RT-PPP accuracy compared with the use of IGU. In this method, the most recent IGU orbits are used as they are compatible with the RT orbits; however, the clock corrections are predicted as a time series using a linear model with four sinusoidal terms. The prediction errors resulting from this method, age of the model and its validity period are discussed. The impact of using the proposed approach is evaluated at a number of sites of known positions by comparing its performance to using IGU orbits and clocks. Moreover, the impact of using predicted corrections is assessed in different scenarios. The experimental results proved validity of the presented approach where positioning mean RMSE of less than 20 cm was maintained during the outage period.
Showing items related by title, author, creator and subject.
Bridging Real-Time Precise Point Positioning in Natural Hazard Warning Systems during Outages of MADOCA CorrectionsEl-Mowafy, Ahmed ; Deo, Manoj (2017)Real-time Precise Point Positioning (RT-PPP) is the primary positioning method used in natural hazard warning systems (NHWS), e.g. for monitoring tsunami and earthquakes. The Japanese Multi-GNSS Advanced Demonstration ...
El-Mowafy, Ahmed; Deo, M.; Kubo, N. (2016)The precise point positioning (PPP) is a popular positioning technique that is dependent on the use of precise orbits and clock corrections. One serious problem for real-time PPP applications such as natural hazard early ...
Real-Time Precise Point Positioning Using Orbit and Clock Corrections as Quasi-Observations for Improved Detection of FaultsEl-Mowafy, Ahmed (2018)Real-time Precise Point Positioning (PPP) relies on the use of accurate satellite orbit and clock corrections. If these corrections contain large errors or faults, either from the system or by meaconing, they will adversely ...