Global Navigation Satellite Systems Engineering, Policy, and Design
The Raquet familyReturn to main article: John Raquet: A Family Affair
COMPASS POINTS
Engineering specialties
Navigation; navigation by signals of opportunity; sensor fusion/integrated avionics; GPS; navigation warfare; software development; stochastic estimation.
Favorite equation
eiπ = –1
By Inside GNSSWhen China joined the GNSS club in 2007, it turned a satnav triumvirate into a quartet.
But some of the limelight needs to fall a little further from center stage — out there where the Indian Regional Navigation Satellite System (IRNSS) and Japan’s Quasi-Zenith Satellite System (QZSS) are not waiting idly in the wings.
By Inside GNSS
John and his wife, Cindy.With an imposing 6’2” physique and a disarming grin, John Raquet rises above the crowd. To colleagues he’s a top-flight engineer and university professor, and director of the Air Force Institute of Technology (AFIT) Autonomy and Navigation Technology Center. But he is also a former all-star basketball player, a preacher, sometime soccer coach, former military officer, and, most definitely, a family man.
By Inside GNSS
Ubiquitous location-aware mobile devices, mainly GPS-enabled smartphones, have led to a boom in location-based services (LBS), which have been revolutionizing businesses and lifestyles. Common uses of LBSs include asset tracking, location-based advertising, emergency roadside service, turn-by-turn navigation, and real-time traffic & road information sharing.
By Inside GNSS
It is by now well known that GNSS-based localization in built-up urban environments can be extremely inaccurate. This is a fundamental problem that hardware enhancements cannot solve.
A GNSS receiver estimates 3D location and timing from pseudoranges from four or more satellites, assuming that these pseudoranges correspond to direct line-of-sight (LOS) paths from each satellite. In urban canyons, however, the signal from a satellite to the receiver suffers from multipath propagation and shadowing.
By Inside GNSS
Figures and TablesThe current stage of GLONASS evolution is aimed at meeting future user requirements of which the most important is the improved accuracy of positioning.
During the implementation of the GLONASS Space Segment Modernization Program (2012–2015), the GLONASS team is facing the situation in which it is not feasible to launch new navigation satellites because the existing constellation is comprised of GLONASS-M satellites operating beyond their guaranteed design lifetime. Nine more GLONASS-M satellites are in ground storage.
By Inside GNSS
A GNSS single-antenna system can be compared to a single-pixel camera. Electromagnetic waves traveling 20,000 kilometers from every overhead direction can reach us. Yet once at the antenna, this diverse set of information is collapsed into a single magnitude and phase value, then sent off to the receiver so that value can be extracted.
By Inside GNSS
Most folks look to a new year as an opportunity for fresh starts and new projects. For the GPS community, however, the October 1 start of the 2016 federal fiscal year (FY16) will likely be more about the hangover — that is, the issues that are hanging over into the next 12 months, unresolved.
At the top of that list of unfinished business are two system decisions: a go/no-go determination on whether the United States will build eLoran as the U.S. backup to GPS and deciding whether or not to choose a new contractor for the GPS III program.
By Dee Ann Divis
There is nothing wrong with provocative, even disruptive, speech or ideas. Turning the world upside down every now and then can shake loose useful innovation along with the shopping lists and pocket change.
But U.S. Secretary of Defense Ashton Carter’s recently revealed comments on GPS (see 360 Degrees article) seem more in the category of “Loose lips sink ships.”
By Inside GNSS
Q: Can you list all the properties of the carrier-smoothing filter?
A: Carrier-smoothing filters, also known as Hatch filters, are commonly used to reduce (“smooth”) the noise and multipath errors in pseudorange measurements by exploiting the high-precision relative distance information from carrier phase measurements. However, carrier-smoothing filters operate on more than just noise and multipath, and this article summarizes the response of such filters to all relevant inputs.
By Inside GNSS
The U.S. stance on satellite navigation has long supported international cooperation and a degree of interoperability. In 2010 the Obama administration even adopted a space policy that said foreign satnav services could be used “to augment and strengthen the resiliency of GPS.”
That was easier in the abstract, however, when the only fully functional GNSS was GPS. Now, with other GNSS services coming online, American officials want to think things through again.
By Dee Ann Divis
At the European Economic and Social Committee’s Space & Society Conference, from left, Daniel Calleja Crespo, director general of European Commission’s DG Growth; EESC Space and Society Project Coordinator Edgardo Maria Iozia, and Giulio Bartolani di Montauto, European Space Agency’s Brussels office.Reporting from Brussels last year, we explained that the then–brand new EU GNSS Regulation had effectively put to bed years of wrangling over who does what in Europe’s GNSS programs. But the issue reared its head again in Brussels recently, in a highly charged discussion hosted by the European Economic and Social Committee (EESC).
By Peter Gutierrez
Renaudin’s children, Satine and Kylian (left); Irish dancing keeps Renaudin on her toes (right).
Return to main article: "Valérie Renaudin: Navigating a Life with GNSS"
COMPASS POINTS
Engineering specialties
Geomatics engineering, design of dynamic position estimation algorithms, GNSS and other sensors, including inertial MEMS, UWB Tx, hybridization filters for navigation, low-cost sensor error modeling and calibration, and magnetic field processing.
By Inside GNSS
