Global Navigation Satellite Systems Engineering, Policy, and Design
GPS III satellite. Lockheed Martin illustrationLockheed Martin announced today (March 15, 2011) that the team it leads in developing the U.S. Air Force’s next-generation GPS III satellites has successfully completed the program’s first major flight-software integration milestone at the company’s software integration laboratory in Newtown, Pennsylvania.
By Inside GNSS
Based on data from Japan’s GPS Earth Observation Network System (GEONET), researchers at the Geospatial Information Authority of Japan (GSI) reported today (March 14, 2011) that the 9.0 magnitude Tohoku earthquake on March 11 in northeast Japan caused an estimated displacement of between roughly 6 and 28 meters along two fault blocks totaling nearly 400 kilometers (248 miles).
By Inside GNSS
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
The GPS community is seething over a January 26 decision by the Federal Communications Commission (FCC) giving a conditional go ahead to a new broadband network with the potential to overwhelm GPS receivers across the country.
By Dee Ann Divis
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
A Coast Guard search and rescue helicopter demonstrates the use of GPS technology at a previous GPS Partnership Council meeting. (Photo: Joe Juarez)Registration is now open for the 2011 GPS Partnership Council meeting on Tuesday, May 3 and Wednesday, May 4 at the Space and Missile Systems Center (SMC) at Los Angeles Air Force Base in El Segundo, California.
These military and industry networking meetings, now in their 11th year, are sponsored by the Los Angeles chapter of AFCEA (Armed Forces Communications Electronics Association) and the USAF GPS Directorate, formerly the GPS Wing.
By Inside GNSS
