The present paper focus on the rectification of QuickBird imagery (Standard PSM True Color image) in order to update the urban planning of Parikia (Paros island, Greece). Although the spatial resolution is sufficient for such application and the radiometric information is often better than the case of existing aerial photos, an accurate geometrical calibration is needed.The methods applied in t...

BACKGROUND The home address is a common spatial proxy for exposure assessment in epidemiological studies but mobility may introduce exposure misclassification. Mobility can be assessed using self-reports or objectively measured using GPS logging but self-reports may not assess the same information as measured mobility. We aimed to assess mobility patterns of a rural population in the Netherland...

Real-time centimeter-level positioning using carrier phase differential GPS (CDGPS) has countless applications in land vehicles. Automobiles, aircraft on taxiways, construction equipment, and farm tractors are just a few types of the vehicles that could benefit from a reliable, accurate sensor producing high-bandwidth position measurements. Most CDGPS systems currently available are initialized...

This report describes the key elements and results of Stanford University’s contribution to the development of the Wide Area Augmentation System (WAAS), its underlying technologies, and alternative methods to provide global vertical guidance to aircraft. WAAS became the first operational space based augmentation system (SBAS) in July 2003. WAAS augments the Global Positioning System (GPS) with ...

In general handheld GPS receivers are used for absolute positioning or for relative positioning using DGPS-services or WAAS/EGNOS signals. The positioning is realized using code pseudo-ranges. Moreover it is well known that some of the handheld receivers use phase-smoothed code for positioning. This means that the phase signal is available and may be used for Precise Differential GPS (PDGPS) po...

In this paper, differential maps of total zenith delay (TZD) estimated by GPS and by Weather Research and Forecasting Model (WRF) numerical data are compared with the TZD by Synthetic Aperture Radar (SAR) Interferometry. This maps are generated by processing a set of interferometric SAR images acquired by the ENVISATASAR mission over the Lisbon region from April to November of 2009. To obtain T...

In this paper we show a new technique, based on the elastic theory, to efficiently produce an estimate of threedimensional surface displacement maps by integrating sparse Global Position System (GPS) measurements of deformations and Differential Interferometric Synthetic Aperture Radar (DInSAR) maps of movements of the Earth’s surface. We propose a linear matrix equation which accounts for both...

A novel method of map matching using the Global Positioning System (GPS) has been developed for civilian use, which uses digital mapping data to infer the <100 meters systematic position errors which result largely from “selective availability” (S/A) imposed by the U.S. military. A method of rapidly detecting inappropriate road centrelines from the set of all possible road centre-lines that a v...

Autonomous drifting buoys that acquire position data using Global Positioning System (GPS) navigation have proven valuable in Lagrangian measurement applications requiring greater accuracy and data density than is available through other technologies such as ARGOS satellite tracking. The limits on measurement accuracy in a GPS drifter are set by the geographic accuracy of the GPS position. Stan...