Global Navigation Satellite Systems Engineering, Policy, and Design
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.
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
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
One of 12 magnetograms recorded at Greenwich Observatory during the Great Geomagnetic Storm of 1859
1996 soccer game in the Midwest, (Rick Dikeman image)
Nouméa ground station after the flood
A pencil and a coffee cup show the size of NASA’s teeny tiny PhoneSat
Bonus Hotspot: Naro Tartaruga AUV
Pacific lamprey spawning (photo by Jeremy Monroe, Fresh Waters Illustrated)
“Return of the Bucentaurn to the Molo on Ascension Day”, by (Giovanni Antonio Canal) Canaletto
The U.S. Naval Observatory Alternate Master Clock at 2nd Space Operations Squadron, Schriever AFB in Colorado. This photo was taken in January, 2006 during the addition of a leap second. The USNO master clocks control GPS timing. They are accurate to within one second every 20 million years (Satellites are so picky! Humans, on the other hand, just want to know if we’re too late for lunch) USAF photo by A1C Jason Ridder. 
Detail of Compass/ BeiDou2 system diagram
Hotspot 6: Beluga A300 600ST
1. RUM DEAL
Moscow, Russia, and Havana, Cuba
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
The 2015 symposium of the Asia-Pacific Space Geodynamics (ASPG) project will focus on Geodesic Datum and Regional and Terrestrial Reference Frame Realizations. It will take place at the Russian Academy of Sciences in Moscow, Russia from August 24 through August 28.
The conference language will be English. Scientific representatives from China and Russia comprise the organizing and program committees.
Themes of particular interest to Inside GNSS readers include presentations on:
Theme 1 Space geodesy
By Inside GNSS
Aerial view of Boulder in OctoberThe tenth meeting of the International Committee on GNSS (ICG) will take place in Boulder, Colorado from November 1 through 6 2015. It will be hosted by the United States and organized by University Corporation for Atmospheric Research (UCAR) on behalf of the U.S. State Department.
It will take place at UCAR headquarters on the Center Green Campus in Boulder.
By Inside GNSS
Students on a field trip at 2014 International School on Satellite NavigationThe 5th International School on Satellite Navigation will take place in the GLONASS Learning Centre in Moscow, Russia from September 14-24.
The event is organized by Roscosmos and JSC Russian Space Systems.
Lectures and hands-on studies cover the history,current status and future applications of GLONASS and GPS. It includes theoreticaf lectures and practical exercises. The first covers satellite navigation fundamentals and the second the combined use of Earth Remote Sensing and GNSS data in specific sectors of the economy.
By Inside GNSS
IPIN 2015 will take place October 13-16 at the Banff Centre, a conference center and school for the arts location in the Rocky Mountain resort town of Banff, a 90 minute drive west of Alberta, Canada.
The indoor postioning and indoor navigation conference includes experts in electronics, surveying and informatics who will discuss this key issue in many emerging applications.
By Inside GNSS
