Global Navigation Satellite Systems Engineering, Policy, and Design
Q: What is Coarse Time Positioning and how does it work?
A: Coarse time positioning is used to provide a position fix using inaccurate time information when tracking sufficiently weak GNSS signals such that the navigation message cannot be extracted reliably. This article presents the key aspects of coarse positioning, including some of its challenges. To start, however, we begin by looking at the role of time within a GNSS receiver.
By Inside GNSS
In-home construction of the first civilian-owned civil GPS spoofer.Over the last few years, several of us in the GNSS community have done our best to convince our colleagues, policymakers, and the general public that unsavory characters with GNSS jammers or spoofers are a genuine threat to GNSS and an orderly society.
"But who would want to use a jammer or spoofer?” people ask.
My response? Hackers, because they can. Thieves planning to snatch expensive cargo. A moonlighting employee in the company car. Worse yet, state actors or terrorists targeting our national infrastructure.
By Inside GNSS
A number of user conferences for customers of Hexagon AB’s precise measurement brands and products will be combined in the Swedish corporation’s second international conference this summer.
By Inside GNSS
A GPS app on a Japanese smartphone. The GPS Council there told the FCC that any signal degradation could jeopardize the Global Positioning System’s standing as a global standard.LightSquared has dropped, for now, efforts to expand its wireless broadband plans to markets in other countries, Inside GNSS has learned.
The Virginia firm was working this summer on proposals to the International Telecommunication Union, including one aimed at addressing compatibility issues between ground stations or “complementary ground components” of mobile satellite services and other frequency-using services.
By Inside GNSS
Next-generation car navigation may well require the ability to identify the lane in which a vehicle is operating on a motorway. This could support advanced driver assistance in general as well as the observation and study of driver behavior and traffic flow. Such road vehicle applications call for sub-meter positioning accuracy, often in real-time — all this preferably at low-cost.
By Inside GNSS
Leica’s Jigsaw Positioning System with LocataLiteLocata Corporation and the U.S. Air Force have announced that the Australia-based company has successfully completed the critical Design Review (CDR) contract phase for a Locata network that will enable the U.S. Air Force to deploy a new ground-based, centimeter-accurate "truth-reference level" positioning system for use in GPS-denied environments.
By Inside GNSS
Consumer demand for positioning information is currently being met by a plethora of wireless positioning technologies. The most popular consumer positioning technology, GNSS, is only one option along with several methods that use cellular networks to provide location, such as wireless local area networks (WLANs), wireless personal area networks (WPANs), radio frequency identification (RFID) tags, and ultrawideband (UWB) communications.
By Inside GNSS
The 43rd PTTI meeting will be held at the Hyatt Regency Long Beach in Long Beach, California on November 14-17, 2011.
Each year, experts meet to exchange precise time and time interval information at the user level, inform government and industry of the technology and its challenges, discuss new technology and review present and future PTTI requirements.
By Inside GNSS
Chris RizosThe founder of Australia’s largest concentration of GNSS research and development efforts has been named head of the International Association of Geodesy, part of the International Union of Geodesy and Geophysics (IUGG)
Chris Rizos put together the Satellite Navigation and Positioning laboratory (SNAP) at the University of New South Wales in the 1990s. He has been researching and writing about high precision technology and applications of GNSS since 1985 and is a professor and head of the surveying and spatial information school at the university.
By Inside GNSS
Hotel Nikko New Century in Haidian, BeijingThis officially sanctioned conference and equipment exhibtion addresses applications, technologies and trends for China’s satellite communications, broadcasting, remote sensing, navigation and positioning.It will be held at Hotel Nikko New Century in Beijing on October 26.28, 2011.
Subjects of most interest to Inside GNSS readers include:
By Inside GNSS
FIGURE 1: System architectureCooperative vehicle safety applications should preferably have two-meter horizontal accuracy and six-meter vertical accuracy, all with a 95-percent availability. The solution must be developed to incorporate lower-cost sensor options, specifically, lower-cost inertial measurement units that can be generally characterized by the gyro drift of 100 degrees per hour and an accelerometer bias force of twice its mass times gravity (two milligals).
By Inside GNSS
This is a 1993 photo of Walter, a German astronaut. He exemplifies the fearless approach to experimentation and the spirit of fun that we are looking for (DLR photo) [Updated June 30] Lucky you – you have three extra days to submit your GNSS application idea to the USA Challenge! The extended deadline is midnight Sunday (Europe) or 3 P.M. (Pacific time) on July 3.
Right now, some team is hard at work in a basement, an office, a dorm room or a lab. They are about to come up with a new, useful and commercially viable idea for a satellite navigation application or location based service.
By Inside GNSS
Steve Koles, president & CEO, Hemisphere GPSHemisphere GPS, Inc., has reported revenue growth of 41 percent and a return to profitability in the first quarter of 2011 for the three months ending March 31.
For the quarter, the Calgary, Alberta, Canada–based company generated $21.2 million in total revenues, compared to US$15.1 million in the first quarter of 2010. Revenues from all market segments increased in the first quarter of this year.
By Inside GNSS
