Global Navigation Satellite Systems Engineering, Policy, and Design
Galileo is Europe’s independent satellite navigation system under civilian control and interoperable with GPS and GLONASS.
By Inside GNSS
Dr. Todd Walter, Stanford UniversityContrary to a widely held public impression, the elimination of GPS Selective Availability in 2000 did not take care of the needs that many users have for enhanced GNSS capabilities.
Indeed, various “augmentations” have been developed to meet the requirements of some applications for better accuracy, availability, or integrity (the assurance of the quality of a signal) than are available from GNSS signals in space.
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
1. NUMBER 3
Cape Canaveral, Florida USA
√ A third GPS IIF has arrived at Cape Canaveral and is being prepped for an October 4 morning launch. Two of the “follow-on” models with better clocks, trickster-foiling technology and more powerful signals are already up. Numbers four and five are waiting to go.
Return to main article: “Vector Delay Lock Loops”
By Inside GNSS
