Precise Point Positioning (PPP) is relatively modern GNSS positioning technique that proved its efficiency comparing with traditional Differential for more than three decades. PPP requires only one receiver collecting observations at unknown station, while two receivers simultaneously known-position station and the other station. Extensive mitigation of different errors essential PPP-collected ...

Currently, high precision kinematic GPS positioning with centimetre level accuracy can only be carried out using differential GPS (DGPS) positioning techniques which require the deployment of base receiver stations. The requirement to deploy base receiver stations, however, spatially limits the operating range of the rover receiver to about 20 km from the base stations. As a result, it not only...

Cross-correlation interference introduced by stronger GPS signals constitutes a major problem in acquisition and tracking. For instance, the presence of a single strong GPS signal can mask other weak signals in indoor positioning. Furthermore, the use of GPS pseudolite can also cause near-far problem due to its proximity to the GPS receiver. The weak signal acquisition and tracking should also ...

There are an increasing number of applications requiring precise relative position and clock offset information. The Global Positioning System has demonstrated precise and drift free position and timing information using CodeDivision-Multiple-Access (CDMA) spread spectrum technology. This technology is widely used and relatively inexpensive, making it attractive in applications beyond the scope...

Continuous GPS networks, typically with a station spacing of about 30km, are still not dense enough to accurately characteristise the dynamics of active faults. Interpolation of these GPS results can improve our understanding of active faults and hence promote related studies. Moreover, even when the networks are densified in order to recover the signature of active faults, the station configur...

The NSW Department of Health (NSW Health) faxed health alerts to general medical practitioners during measles outbreaks in March and May 2006. We conducted a retrospective cohort study of randomly selected general practitioners (GPs) (1 per medical practice) in New South Wales to investigate the effectiveness of faxing health alerts to GPs during a communicable disease outbreak. Fax transmissio...

Differential Global Positioning System (DGPS) provides differential corrections for a GPS receiver in order to improve the navigation solution accuracy. DGPS position signals are accurate, but very slow updates. Improving DGPS corrections prediction accuracy has received considerable attention in past decades. In this research work, the Neural Network (NN) based on the Gaussian Radial Basis Fun...

A number of public codes exist for GPS positioning and baseline determination in off-line mode. However, no software code exists for DGPS exploiting correction factors at base stations, without relying on double difference information. In order to accomplish it, a methodology is introduced in MATLAB environment for DGPS using C/A pseudoranges on single frequency L1 only to make it feasible for ...

Global Positioning System (GPS) is being used in aviation, nautical navigation and the orientation ashore. Further, it is used in land surveying and other applications where the determination of the exact position is required. Although GPS is known as a precise positioning system, there are several error sources which are categorized into three main groups including errors related to satellites...

Tropospheric delay is one of the major error sources in GPS positioning. The delay of radio signals caused by the troposphere can range from 2 m at the zenith to 20 m at lower elevation angles. In a wide area differential system, tropospheric delays are corrected locally by users using an empirical tropospheric model, with or without meteorological observations. This can easily result in residu...