Alison Brown is the President and Chief Executive Officer of NAVSYS Corporation, which she founded in 1986. NAVSYS Corporation specializes in developing next generation Global Positioning System (GPS) technology. Dr. Brown has a PhD in Mechanics, Aerospace, and Nuclear Engineering from UCLA, an MS in Aeronautics and Astronautics from MIT, and an MA and BA in Engineering from Cambridge Universit...

The National Institute of Standards and Technology (NIST) is deploying disciplined oscillators that are referenced to the UTC(NIST) time scale through common-view observations of Global Positioning System (GPS) satellites. We present measurement results from four NIST disciplined oscillators (NISTDOs), three located in the United States, and one located in Concepción, Chile. These devices repli...

The aims of this study were, first, to analyse the differences between referees and assistant referees in 20and 30-metre straight line sprinting test performance and in the maximum speeds registered in football matches; and, second, to analyse the differences between the maximum speeds registered in matches and in the straight line sprinting test. Twenty referees from the Spanish Third Football...

This paper focuses on the break-taking behaviour pattern of long-distance freight vehicles, providing a new perspective on the study of behaviour patterns and simultaneously providing a reference for transport management departments and related enterprises. Based on Global Positioning System (GPS) trajectory data, we select stopping points as break-taking sites of long-distance freight vehicles...

[1] The 26 December 2004 Sumatra earthquake (Mw 9.2–9.3) generated the most deadly tsunami in history. Yet within the first hour, the true danger of a major oceanwide tsunami was not indicated by seismic magnitude estimates, which were far too low (Mw 8.0–8.5). This problem relates to the inherent saturation of early seismicwave methods. Here we show that the earthquake’s true size and tsunami ...

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...

In this paper, a low complexity long pseudo noise (PN) code acquisition scheme is proposed for spread spectrum systems including global positioning system (GPS) and code division multiple access (CDMA) system. By using a phaseshift-network, the proposed scheme has less complexity than the conventional dual correlating sequential estimation scheme. From the analytic and numerical results, it is ...

• The combination of signals planned to be available for civil use from the U.S.'s Global Positioning System (GPS) and the former U.S.S.R.'s GLONASS system offers the promise of an accurate and economical sole-means navigation system for civil aviation. An FAA-sponsored program at Lincoln Laboratory has examined the technical issues associated with the integrated use of the two autonomous syste...

A methodology for developing a simple theoretical model for calculating global insolation on a horizontal surface is described in this paper. The input parameters to the model are the latitude of the desired location and the amount of total precipitable water content in the vertical column at that location. Both the parameters are easily measurable with inexpensive instrument such as global pos...

Comparison of simultaneous Global Positioning System (GPS) and water vapor radiometer (WVR) measurements at Goldstone over 82 days in the period between June 25 and October 6, 1996, shows agreement in zenith wet path-delay estimates to <6 mm rms. The level of agreement is consistent with the expected levels of GPS and WVR errors. This method shows considerable promise for improving the accuracy...