201509 September/October 2015

September 11, 2015

ESA Launches Two Galileo Satellites

Two Galileo satellites were carried into space today (September 10, 2015) with a successful launch at 10:08 p.m. (EDT) ((02:08 GMT on September 11) from the Soyuz Launch Complex at the European spaceport in French Guiana.

Read More >

By Inside GNSS
September 7, 2015

Let Us Now Praise

When 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.

Read More >

By Inside GNSS

Alternative PNT

Senior Research Engineer, Stanford University GPS Lab

At one time, GPS was expected to supplant a wide range of navigation technologies in the world’s positioning, navigation, and timing (PNT) portfolio. But an unexpected thing happened along the way.

Read More >

By Inside GNSS

John Raquet: A Family Affair

John and his wife, Cindy.

John Raquet’s Compass Points

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.

Read More >

By Inside GNSS

GPS Confidential

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.

Read More >

By Inside GNSS

Urban Localization and 3D Mapping Using GNSS Shadows

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.

Read More >

By Inside GNSS

GLONASS for Precise Navigation in Space

Figures and Tables

The 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.

Read More >

By Inside GNSS

Single Antenna, Dual Use

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.

Read More >

By Inside GNSS

New Fiscal Year Begins with Unfinished GPS Business

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.

Read More >

By Dee Ann Divis

LightSquared Launches New GPS Receiver Tests

LightSquared’s proposed GPS receiver tests are relying on an outdated standard of GPS accuracy, a choice some experts suggest is a maneuver aimed at dramatically lowering the bar the would-be wireless broadband company has to meet for showing noninterference to GPS signals.

Read More >

By Inside GNSS