Global Navigation Satellite Systems Engineering, Policy, and Design
Here’s the coolest “technology-meets-ingenuity-meets-sustainable-economics” story that I’ve heard in a long time: the International Sun-Earth Explorer-3 (ISEE-3) Reboot Project, a crowd-funded rescue mission to repurpose a 36-year-old NASA spacecraft.
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. SMART BALL
Portland, Oregon USA
√ Adidas has designed every official World Cup ball since 1970. And that’s not all! The Adidas Innovation Team in Portland, Oregon, spent 4 years on a smart soccer ball with a “six-axis MEMS accelerometer sensor package” that can detect speed, spin, strike and flight path data and whip it on over to the special GPS app on your iPhone. The app interprets the data for you, coaches you, and keeps a video to show your friends. On sale now for only $299.
Washington, D.C., has a peculiarity of seasons. While most of the world marks the shifts between winter and spring, summer and autumn, the politicos on the streets of the U.S. capital count the passage of time in two-year increments.
New operatives and appointees flock to the centers of power in the early days of each administration and the opening of each Congress, then migrate to friendlier climes as congressional elections loom and the administration winds down — as it is now.
By Dee Ann Divis
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.
By Inside GNSS
Q: How do measurement errors propagate into GNSS position estimates?
A: Not surprisingly, GNSS positioning accuracy is largely dependent on the level of measurement errors induced by orbital inaccuracies, atmospheric effects, multipath, and noise. This article discusses how, specifically, these errors manifest as position errors.
By Inside GNSS
Return to main article: "An Airborne Experimental Test Platform"
By Inside GNSS
Michel Monnerat’s Favorite EquationMentors
By Inside GNSS
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 600STJPL uses GPS to find Sierra Nevada water weight; Near collision of drone and regional jet prompts questions, West Antarctic ice sheet melt at “point of no return,” First Galileo FOC satellites at launch site, China’s GBAS tested in Tianjin
By Inside GNSS
Well, I could have taken up the subject of the deteriorating condition of U.S./Soviet, excuse me, U.S./Russian relations. But there are only so many windmills that I have time to tilt at.
So, rather than tracing the dissolution of bilateral GNSS cooperation in the wake of Russia’s reclaiming the Crimea and, who knows, perhaps eventually a large swath of eastern Ukraine, I thought I’d turn to an only slightly more remediable issue — GNSS carriage requirements.
By Inside GNSS
Clockwise from left: (a) article equations, (b) the probablility of acquiring a single satellite to the power of the nyumber of satellites in view, (c) Indoor scenario of signal collection at ISAE navigation lab, ToulouseWorking 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.
By Inside GNSS
Q: How do you compute a relative position using GNSS?
A: In many applications the absolute position of an object is less important than the relative position to other objects in the vicinity. An obvious example is a collision avoidance system, wherein the proximity of nearly vehicles is much more important than whether the vehicles are located on street “X” or “Y.”
By Inside GNSS
SIDEBAR: Michel Monnerat’s Compass Points
“I was born in Arles, in the south of France,” says Michel Monnerat, “but I left France before my first birthday. We moved many times, from place to place.”
Monnerat’s father worked for a civil engineering company, specializing in maritime works — harbor construction, coastal protection, and such. His family lived in Ivory Coast, Cameroon, and Tunisia, but Monnerat spent most of my early life in Lomé, the capital city of Togo.
By Inside GNSS
Europe has been talking up its European Geostationary Navigation Overlay Service (EGNOS, for short) — and why shouldn’t it? Talking about Galileo doesn’t get satellites off the ground. EGNOS, on the other hand, is up and running, and has been since 2009. If the object is to build confidence in European savoir faire, why not talk about a real success like EGNOS?
By Peter Gutierrez
