Global Navigation Satellite Systems Engineering, Policy, and Design
August 1994, early morning. Spain’s Central Pyrenees Mountains still in darkness.
At the outset of an ascent to a 3,000-meter peak along the international border, one of the co-authors encounters a group of tourist hikers who have begun searching for a colleague who had left the camp the previous evening. In the pre-sunrise gloom, helicopters cannot yet operate.
A week later, the body of the hiker is found. The rescue efforts came, unfortunately, too late.
By Inside GNSS
Return to main article: "Demystifying GLONASS Inter-Frequency Carrier Phase Biases"
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. GROWTH SPURT
California/Nevada, USA
√ The age of the Sierra Nevada mountains — home of Yosemite Valley and Lake Tahoe — is puzzling to geodesists. Integrating GPS and inSAR, Universities of Nevada and Glasgow teams studied the area’s uplift and found that it is growing by 1 to 2 millimeters per year. The verdict? The entire range could have arisen in less than 3 million years.
iNsight team members: (L to R) Zeynep Elmas and Terry Moore (Nottingham), Marek Ziebart (UCL), Mojtaba Bahrami (at that time of UCL), Carl Milner (then of Imperial), Alper Ucar (Westminster), Chris Hide (Nottingham), Shaojun Feng (Imperial), Ziyi Jiang (UCL) and Paul Groves (UCL). Not pictured, Washington Ochieng (Imperial) and Izzet Kale (Westminster).The diversity and redundancy provided by multiple, independent, compatible, and in some respects, interoperable GNSS systems must be a good thing, right?
Well, almost certainly. But as with many things in life and technology, the devil’s in the details. And, as the varied characteristics and design specifications of new GNSSes and regional systems become clearer, it may not be too early to sort out those details.
By Inside GNSS
As Desi Arnaz often said to Lucille Ball during an “I Love Lucy” episode on TV, “You’ve got some ’splaining to do.”
I refer, of course, to the untoward and unexpected initiative by the British Ministry of Defense (MoD) to patent the technical innovations that underlie the planned next generation of civil GNSS signals.
By Dee Ann Divis
Return to main Washington View article: "USPTO Nears Approval of Troubling British Patent on New GPS Civil Signal"
By Dee Ann Divis
Tracking range to a transceiver transmitting 10 watts per signalReturn to main article: "Truth on the Range"
By Inside GNSS
