[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 ...

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...

Positioning can be done by means of triangulation in which triples of position-aware nodes estimate a neighbor’s position with the help of distances. If a larger number of nodes exist, multiple position estimates can be averaged to yield a more precise mean position. Rather than applying equal weights to each position estimate, we propose an unequal weighting scheme which emphasizes those summa...

In general people often spend 80-90% of their time in indoor environments, which include shopping malls, libraries, airports, universities, schools, offices, factories, hospitals, among others. In these environments, GPS does not work properly, causing inaccurate positioning. Currently, when performing the location of people or objects in indoor environments, no single technology can reproduce ...

There are three general scenarios for the use of pseudolites in deformation monitoring systems; namely GPS augmented with pseudolites, pseudolite-only and pseudolite ‘inverted’ positioning. This paper focuses on the results and analysis of experimental data collected for these three pseudolite scenarios. The results suggest that the use of helical antennas can reduce pseudolite multipath error....

Complex tectonic and non-tectonic movements exist in the Tianshan area. However, we have not acquired good knowledge of such movements yet. In this study, we combine Global Positioning System (GPS), the Gravity Recovery and Climate Experiment (GRACE) and Surface Loading Models (SLMs) data to study the seasonal vertical crustal displacements in the Tianshan area. The results show that all three ...

Particle filter-based inertial positioning promises infrastructure-less positioning, but previous research have not provided an understanding of, how the positioning accuracy of such systems depends on the layout of building structures. This poster presents initial result for the impact of the layout of building structures on the positioning accuracy using a particle filter-based inertial posit...

Position determination is one of the key-elements of Location Based Services (LBS). One popular approach to positioning for LBS is using a Global Navigation Satellite System (GNSS). With such a system, three-dimensional positioning is available anywhere on, and above the Earth, in principle without any local or regional infrastructure. On the other hand, as satellite based radio positioning rel...

Current military distributed virtual environments (DVEs) can not realistically allow systems to navigate using Global Positioning System (GPS) timing and position signals. Therefore, we designed and implemented the Virtual Global Positioning System Receiver (VGPSR) and added modules to the Solar System Modeler to enable GPS broadcast. The Solar System Modeler is a virtual environment applicatio...