Information Technology

  2010 APR 20 - (VerticalNews.com) -- "Dilution of precision (DOP) is a fundamental concept in satellite navigation and surveying. A deeper understanding of this concept can be achieved through the means of 3D immersive visualisation," investigators in Leicester, the United Kingdom report.

  "In this article, we present a method for visualising and exploring the spatial variation of DOP and discuss its presentation within an immersive virtual environment. The work demonstrates a real-time simulation of global positioning system (GPS) satellite geometry, modelled and visualised within a virtual representation of the university campus. The number of satellites visible to the receiver is modelled in real time as a user walks through the university campus. During this process, the changing satellite geometry is visualised in both 3D and aerial views. Various DOP values update to the screen against a pseudo-realistic building backdrop as the user travels. Both the aerial views and the changing volumes of the tetrahedra drawn in 3D provide an effective way of interpreting why exceptionally large or small horizontal DOP and vertical DOP values can occur in an urban context," wrote J. Li and colleagues, University of Leicester ...read more

  2010 APR 20 - (VerticalNews.com) -- "To improve the efficiency of planning and designing silt dam systems, this article employs theories and technologies of collaboration and distributed virtual geographic environments (VGEs) to construct a collaborative virtual geographic environment (CVGE) system. The CVGE system provides geographically distributed users with a shared virtual space and a collaborative platform to implement collaborative planning," scientists in Hong Kong, People's Republic of China report ...read more

  2010 APR 20 - (VerticalNews.com) -- "One of the major sources of uncertainty associated with geographical data in GIS arises when they are the outcome of a sampling process. It is well known that when sampling from a spatially autocorrelated homogeneous surface, stratification reduces the error variance of the estimator of the population mean," scientists writing in the International Journal of Geographical Information Science report ...read more