[1] We present the first two aircraft Global Positioning System (GPS)-reflection altimetry measurements, the most precise GPS ocean-altimetry measurement, and demonstrate the altimetric precision and spatial resolution necessary to map mesoscale eddies. Our first experiment demonstrated a 14-cm precision single-satellite ocean altimetry measurement while our more recent experiment demonstrates ...

A hybrid positioning system is merely one in which multiple systems are used for positioning purposes. This virtually always, though not necessarily, includes Global Positioning System (GPS) as it is the only global positioning network currently. Combination of mobile network and GPS positioning techniques provide a higher accuracy of mobile location than positions based on a standalone GPS or ...

In this paper, we survey the global positioning system (GPS)-less vehicular localization methods using dedicated short range communication (DSRC). Time of arrival (TOA), which is one of the radio-based ranging techniques, is used in the methods to localize a vehicle. Through the localization methods using DSRC, vehicles can handle GPS error or the situations of no GPS location data when they ar...

One of the most difficult and expensive tasks in making noise pollution maps is the collection and processing of the data needed to create acoustic models. In the case of road traffic noise maps, obtaining speed data for light and heavy vehicles a problem that has usually been avoided by using a road’s speed limit or by making assumptions based on experience from similar road types. Here global...

This report describes a simulation model developed to evaluate the impact of using Intelligent Transportation Systems (ITS), such as Global Positioning Systems (GPS) for bus tracking, on controlling buses in wide-area transit networks. Control strategies with ITS will be compared against those without ITS (i.e., they do not rely on communication or tracking). The model is developed using a gene...

1.1 GPS – benefits & constraints The Global Positioning System (GPS) is an all-weather, global, satellite-based, roundthe-clock system developed by the U.S. Department of Defense, which since the early 1980s has been available to the civilian community and has truly revolutionized navigation, surveying and geodesy. GPS is based on a constellation of up to 30 satellites orbiting the Earth, broad...

The Global Navigation Satellite System (GNSS) plays an important role in positioning and navigation applications. The Global Positioning Service (GPS) augmentation is to achieve more reliable and accurate navigation solutions. The presently available traditional GNSS receivers are hardware based receivers which are not flexible and cannot be easily upgraded to acquire the signals from other GNS...

Today, there are two Global Navigation Satellite Systems (GNSS) that are fully operational and commercially available to provide all-weather guidance virtually 24 h a day anywhere on the surface of the earth. GNSS are the collection of localization systems that use satellites to know the location of a user receiver in a global (Earth-centered) coordinate system and this has become the positioni...

The Global Positioning system (GPS) is used for navigation and associated tasks in wide variety of applications. One of the primary modes of GPS operation is differential GPS. Differential GPS allows more accurate positioning than stand-alone GPS. Many new applications are possible because of the increased accuracy obtained through differential GPS. In this paper the techniques and methods of d...

Generally, accuracy of GPS(Global Positioning System) is higher than that of cellular network. But in tall building urban area or indoor, relatively weak GPS signal makes the positioning unstable and inaccurate. TDOA(Time Difference of Arrival) is one of the most widely used positioning methods in cellular mobile communication systems, but its accuracy is not high enough to meet the growing dem...