GNSS Hotspots | November 2015 - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design

GNSS Hotspots | November 2015

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

Annapolis, Maryland and Kings Point, New York USA

Annapolis, Maryland and Kings Point, New York USA
√ For cybersecurity reasons, the U.S. Naval Academy has rebooted training in the ancient art of celestial navigation, nearly 20 years after they mothballed their sextants in favor of the much more accurate (and printed almanac-free) GPS. Students get three hours of instruction, not enough to wield a sextant like an old salt — but advanced courses are planned. Celestial navigation is a solid back up if GPS becomes unreliable for any reason said Capt. Timothy Tisch, an instructor at the U.S. Merchant Marine Academy, which never stopped teaching the traditional skills. What if the trainees actually have to use it? Positioning will be much less accurate, but it can’t be hacked.

Long Island, New York
√ The ongoing debate about GNSS and privacy is slowly resolving into new law and custom. Recently, the parents of two Long Island children with autism and the North Merrick school district reached an agreement about GPS tracking in school. The boys, aged 8 and 10, had wandered away from home and school 14 times in two years, despite alarms and extra locks. The parents wanted to use tracking devices and the school said no, it “threatened the confidentiality of other students.” After a month-long dialog, the school relented, saying they wouldn’t block a device designed for child safety.

Salzburg, Austria and Delft, Netherlands
√ Don’t trust your fitness tracker. Researchers in Austria and the Netherlands have found that the distance measured by GPS, on average, exceeds the actual distance traveled and they’ve figured out a formula for predicting the error. Their open access paper, published in the International Journal of Geographical Information Science, cites propagation delay, ephemeris error, satellite clock drift, hardware error, signal reflections, or too few GPS satellites in the sky as causes. This problem is magnified when multiple segments are added together. If you can’t trust atomic clocks, who can you trust?

London, England
√ The vast accessible memory bank of London’s cabbies has fallen victim to satellite navigation and Uber. The largest training school for London Black Cab drivers, where trainees spend several years memorizing 25,000 streets and thousands of points of interest, will close in December. Brains may shrink as a result. A study of “humans with extensive navigation experience” at University College London found a significantly larger posterior hippocampus (responsible for long-term memory and spatial navigation) in licensed London taxi drivers, which grew during their grueling course of study. The cabbies hold that memory still beats technology. “I’m an ambassador for this great city that we work and live in, and you can’t get that from a GPS,” says Brian Nayar, an instructor of The Knowledge.