Global Navigation Satellite Systems Engineering, Policy, and Design
GNSS receivers and users, along with the critical infrastructures and services they support, face a growing threat from jamming, spoofing, and meaconing (JSM) events.
Several proposals for GNSS spoofing detection and signal authentication have been proposed over in recent years. These have focused mainly on adding cryptography elements to the GNSS signals and detecting RF characteristics of undesired signals.
By Inside GNSS
The past 15 years have witnessed tremendous developments of new and modernized satellite-based navigation (satnav) systems, including GNSSs, regional systems, and space-based augmentation systems (SBASs). These have been enabled by the original designs of GPS and GLONASS and, in turn, have stimulated the design of satnav signal structures with different characteristics from those pioneer systems.
By Inside GNSS
[Updated June 3, 2013] With the budget vise tightening, top Pentagon managers are readying some potentially dramatic changes to the GPS constellation — changes that promise to lower both the cost of the satellites and the expense of putting them into orbit.
The first changes would be subtle and are linked to buying the next block of GPS III satellites — a decision that sources confirm will be made by the end of September.
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. PESTS
State of California, USA
√ The California Agriculture department is using collective intelligence and GPS to “report a pest.” State residents can download the new CDFA smartphone app and use it to photograph and report bad bugs when they see ‘em. Those with iPhones can choose to send GPS coordinates for quick response to invasive pest emergencies.
The fourth China Satellite Navigation Conference (CSNC 2013) wound up its three-day run on May 17 in Wuhan — by all measures a clear success for an event that has become the nation’s leading international GNSS forum.
A key take-away from the event: China is rapidly preparing to bring BeiDou products and technology into the international marketplace is encouraging its industry to build an internationally applicable knowledge base in standards, patent law, and intellectual property rights (IPR).
By Inside GNSS
Prof. Jingnan Liu, Chinese Academy of EngineeringSince announcing plans in late 2006 to build its own GNSS system — BeiDou-2 (BDS), China proceeded quickly to establish a fully operational regional system late last year with a clear plan to complete a global system by 2020.
Beginning with its first launch in April 2007, BDS has put 16 satellites in orbit, some in dual launches, with 14 BeiDou space vehicles currently transmitting healthy signals: 5 in geostationary orbits (GEO), 5 in inclined geosynchronous orbits (IGSO), and 4 middle Earth orbit (MEO) spacecraft.
By Inside GNSS
Di Qiu at the site of her current employerSIDEBAR: Di Qiu’s Compass Points
Landing all-weather aircraft safely in storms. Protecting sensitive data not only through encryption but based on the location at which it is being accessed. Ensuring that accurate and timely information reaches first responders responding to emergencies.
Although still in the early part of her career, Di Qiu has already made significant contributions to these crucial applications of navigation technology.
By Inside GNSS
Taylor’s SeriesEngineering Specialties
Engineering Mentors
By Inside GNSS
It’s all about the backups now. The alternatives. The gap-fillers.
Back in the 1990s, when I first came across the U.S. Federal Radionavigation Plan (FRP), I learned that the rise of the Global Positioning System drove the biannual FRP process because of the expectation that GPS would enable the government to shut down many pieces in the hodgepodge of positioning, navigation, and timing (PNT) systems.
By Inside GNSS
Return to main article: "MUSTER: A Collaborative GNSS Receiver Architecture for Weak Signal Processing"
By Inside GNSS
