Global Navigation Satellite Systems Engineering, Policy, and Design
Q: Does the magnitude of the GNSS receiver clock offset matter?
A: It is well known that GNSS receiver clocks drift relative to the stable atomic time scale that ultimately defines a particular GNSS system in the first place. GNSS receiver manufacturers, however, try to limit the magnitude of the time offset to within some predefined range.
By Inside GNSS
For the complete story, including figures, graphs, and images, please download the PDF of the article, above.
Integer carrier-phase ambiguity resolution is the key to fast and high-precision GNSS positioning and navigation. It is the process of resolving the unknown cycle ambiguities of the carrier-phase data as integers. Once this has been done successfully, the very precise carrier-phase data will act as pseudorange data, thus making very precise positioning and navigation possible.
By Inside GNSS
Equation: signal variance for a “ring of scatterers” modelIndoor GNSS propagation environments are characterized by multiple reflected signal paths (multipath) terminating at the receiver. Consequently, the received signal’s amplitude, phase, and perceived angle of arrival attributes vary randomly as the receiver moves. This has created significant interest among receiver designers and manufacturers to develop powerful processing for GNSS handsets such that these can operate effectively in indoor faded environments.
By Inside GNSS
Figures 1 & 2For the complete story, including figures, graphs, and images, please download the PDF of the article, above.
Growing dependence on GNSS for positioning, navigation, and timing (PNT) has raised a parallel concern about the potential risks of signal interference. The popular press has recently highlighted accounts of car thieves using GPS jammers, solar flares pumping out L-band radiation, and faulty television sets causing havoc to GPS receivers across an entire harbor.
By Inside GNSS
Figure 1 & Table 1For the complete story, including figures, graphs, and images, please download the PDF of the article, above.
Recent years have seen GPS receivers built in as a standard feature in many consumer products. A growing number of mobile phones, personal navigation devices, netbooks and tablets are equipped with GPS receiver chips and navigation software that enable consumers to navigate from A to B or find their nearest coffee shop. According to Berg Insight, annual shipments of GPS-equipped mobile phones are estimated to reach 960 million devices in 2014.
By Inside GNSS
Galileo Test and Development Environment (GATE) Photo: iFENThe 2011 International Summer School on GNSS will take place July 20 to July 30 at the GATE facility in Berchtesgaden, Germany. GATE is the German Galileo Test and Development Environment that opened in February.
By Inside GNSS
The International Committee on GNSS (ICG), is a voluntary United Nations–backed association that brings together GNSS and augmentation providers — including the United States, Russia, European Union, China, India, and Japan — and associate members representing key user communities.
By Inside GNSS
The 18th International Conference on Integrated Navigation Systems will take place at Central Scientific & Research Institute "Elektropribor" in St. Petersburg on May 30-June 1, 2011.
By Inside GNSS
Exhibition floor at a previous Satellite Navigation Forum.The annual International Satellite Navigation Forum, which emphasizes GLONASS innovations and commercial applications, will take place at the Expocentre Fairgrounds in Moscow, Russia on June 1 and June 2, 2011.
It is held at the same location as the Navitech Expo navigation systems, technologies and services trade fair, which runs from June 1-3.
By Inside GNSS
The Geospatial Building at the University of NottinghamA two-day workshop on GNSS receivers will take place at the Geospatial Building at the University of Nottingham Innovation Park on April 14 and 15, 2011.
In addition to talks by GNSS experts, the workshop features product demonstrations, using the test facilitiies at GRACE, the GNSS Research and Applications Center of Excellence. These include GPS and Galileo full constellation Spirent simulator, signal record and replay devices and the roof-based fixed test track designed for dynamic research and testing.
By Inside GNSS
The 2011 EU GNSS Receiver Workshop will take place at the University of Nottingham’s Geospatial Building on April 14 and 15.
In addition to talks, the event features project demonstrations that make use of the GNSS Research and Applications Center of Excellence (GRACE) test facilities. These include a GPS and Galileo full constellation Spirent simulator, signal record and replay devices and the roof-based fixed test track designed for dynamic research and testing.
By Inside GNSS
Marriott Convention CenterThe American Society of Civil Engineers will offer a day-long program on Monday, March 21 at SPAR International 2011 that will focus on real-time GNSS positioning and using the 3D Global Spatial Data Model
Bill Henning, senior geodesist for the National Geodetic Survey, will lead the morning session. With more than 43 years of experience in all phases of surveying technology, he is helping to develop guidelines and support methodology for real time GNSS position with state, national, and international organizations.
By Inside GNSS
Fira de Barcelona, Monjuic venueThe GlobalGEO Fair will take place in the Monjuic Venue, Hall 6 at Fira de Barcelona exhibition center in Barcelona, Spain from March 15 to March 17.
The fair features the latest products for GPS navigation, 3D mapping, geographic information systems, photogrammetry, teledetection, geodesics, topography, satellite navigation, intelligent transport systems and communications.
By Inside GNSS
