Global Navigation Satellite Systems Engineering, Policy, and Design
The satellite-based NextGen program is in trouble — no question about it.
The Federal Aviation Administration (FAA) air traffic modernization effort will likely cost triple its original $40-billion program budget and need an extra decade — until 2035 or beyond — to reach completion, according to 2014 testimony by Department of Transportation (DoT) Inspector General Calvin Scovel.
By Dee Ann Divis
SBAS and RNSS: The Unsung Heroes of GNSS
Okay, if I had wanted to pander to GNSS fans, I might have called this, “Making Great Greater.”
But there are only so many superlatives that can be lathered on this remarkable technology before simple praise turns into hagiography.
So, it’s time once more to give a little love to those unsung heroes of GNSS: the augmentations and regional navigation satellite systems.
By Inside GNSS
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
Catching thieves in California, Galileo satellites test Einstein, Russian space agency remodel, and 911 training for operators who can’t read maps.
By Inside GNSS
Europe’s space community rang in the New Year with two of its brightest annual fixtures: the European Union (EU) Space Policy conference in Brussels and the European Space Agency (ESA) media briefing in Paris.
The events brought out all of the relevant voices and served to illustrate not only the disposition of materiel and troops but also their intent and even the level of morale.
By Peter Gutierrez
Working Papers explore the technical and scientific themes that underpin GNSS programs and applications. This regular column is coordinated by Prof. Dr.-Ing. Günter Hein, head of Europe’s Galileo Operations and Evolution.
With the support of the European Space Agency (ESA), a European team designed a frequency- and time-transfer process and validated its performance in a complex navigation test bed. This two-way time-transfer technology took advantage of the following:
By Günter W. Hein
Figure 1, 3, 4 & 5Q: What is Doppler collision and is it a problem in GNSS?
A: Doppler collision is a physical effect in code-division multiple access (CDMA) systems where code measurement errors are observed due to cross-correlation effects. Doppler collision may occur when the Doppler frequency between signals from two different transmitters is smaller than the code lock loop bandwidth.
By Inside GNSS
Small GPS jammers, particularly the “personal privacy devices” readily available on the Internet, pose one of the greatest risks to the nation’s critical infrastructure, according to a now-public Homeland Security assessment.
By Dee Ann Divis
One of 12 magnetograms recorded at Greenwich Observatory during the Great Geomagnetic Storm of 18591996 soccer game in the Midwest, (Rick Dikeman image)Nouméa ground station after the floodA pencil and a coffee cup show the size of NASA’s teeny tiny PhoneSatBonus Hotspot: Naro Tartaruga AUVPacific lamprey spawning (photo by Jeremy Monroe, Fresh Waters Illustrated)“Return of the Bucentaurn to the Molo on Ascension Day”, by (Giovanni Antonio Canal) CanalettoThe 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 diagramHotspot 6: Beluga A300 600ST1. DÉJÀ VU
Annapolis, Maryland and Kings Point, New York USA
For an organization with its name, the Federal Communications Commission (FCC) is a remarkably opaque public entity.
Such is the case with the agency’s inaction on requests by foreign GNSS services to waive the so-called FCC Part 25 rules that require licensing of non-Federal receive-only Earth stations (e.g., GNSS receivers) operating with non-U.S. licensed space stations (i.e., satellites).
Although at least one such request has reportedly been submitted, the FCC has not even acknowledged it, let alone moved to render a decision on the request.
By Inside GNSS
Riley and his son, Ben.Return to main article: Stuart Riley: Right Turn from the Wrong Path
COMPASS POINTS
Professional Path
Riley received a Ph.D. in electrical engineering at the University of Leeds (United Kingdom) where he then worked as a research fellow in 1994–5. After that, he joined Trimble Navigation Ltd. as a GNSS receiver designer. He is based in Sunnyvale, California, where since 2010 he has served as the company’s engineering director
By Inside GNSS
Equations 1 – 10The constant growth and evolution of the positioning, navigation, and timing (PNT) market generate demands for more and more added-value applications and services relying on GNSS signals, with expectations for improved accuracy and availability. Some services may also rely on added-value content other than navigation messages, for example, higher data volume with less latency, such as the data carried by satellite-based augmentation system (SBAS) services and the Galileo Commercial Service.
By Günter W. Hein
Q: How Important Is It to Synchronize the Code and Phase Measurements of a GNSS Receiver?
A: Precise timing lies at the heart of GNSS implementation and operation and is generally well understood in terms of synchronizing individual satellites and/or receivers. Recent results, however, have demonstrated that timing of code and phase measurements in a receiver can have significant implications for the timing community in particular.
By Inside GNSS
Speakers at the low-in-profile but high-in-content International Association of Institutes of Navigation (IAIN) conference in Prague this year threw into stark relief some of the big GNSS programs and even bigger GNSS questions.
By Peter Gutierrez
