For engineering applications high precision GPS with survey grade receivers allows positioning in real-time to a centimetre level of precision. Many of the error sources affecting the GPS signal have been significantly removed in order to achieve such high precision. However, one error source that is difficult to mitigate is that of the multipath error. GPS signal multipath occurs when the GPS ...

BACKGROUND Given the importance of community-based research, there is a need to ensure the quality of data obtained from such studies. However, research has been considered a low priority for most GPs. OBJECTIVES To assess the quality of data reported by GPs in a large community-based study. METHODS Men were recruited as part of a population-based study on prostate-specific antigen (PSA) te...

We present a new approach to remote sensing of water vapor based on the global positioning system (GPS). Geodesists and geophysicists have devised methods for estimating the extent to which signals propagating from GPS satellites to ground-based GPS receivers are delayed by atmospheric water vapor. This delay is parameterized in terms of a time-varying zenith wet delay (ZWD) which is retrieved ...

NAVSYS High Gain Advanced GPS Receiver (HAGR) uses a digital beam-steering antenna array to provide additional gain in the direction of the GPS satellite signals. This increases the received signal/noise ratio on the satellites tracked and also improves the accuracy of the pseudo-range and carrier-phase observations. The directivity of the digital beams created from the antenna array also reduc...

This paper shows a distributed object-oriented architecture to provide GPS data to GIS applications. Data captured in real time by GPS units are sent via radio to the computer. Several sources of this real data in addition to simulated GPS data are distributed in a computer network. These servers of GPS data can be accessed by distributed client applications. A CORBA based infrastructure provid...

The Eurasian Curlew is an endangered long-lived shorebird breeding in grassland and moorland, with declining numbers across its range due to habitat loss former hunting. In this context, any additional adult mortality can have a noticeable impact on population dynamics, hence extinction risk. We report case of GPS-tagged individual which track revealed unusual stopover at the bottom wind turbin...

Due to widespread use of Global Positioning System (GPS) in different applications, the issue of GPS signal interference cancelation is becoming an increasing concern. One of the most important intentional interferences is spoofing signals. An effective interference (delay spoof) reduction method based on adaptive filtering is developed in this paper. The principle of method is using adaptive f...

OBJECTIVE To compare the quality of care provided by general practitioners participating in diabetes shared-care registers with that provided by GPs not using registers. DESIGN Cross-sectional comparison using Health Insurance Commission (HIC) data for patients attending the GPs. PARTICIPANTS AND SETTING 155 GPs using diabetes registers, 459 GPs not using registers, and their patients with ...