Two important new signals — or rather, one signal and one group of signals — became available for military users worldwide last week. Satelles made an exciting announcement of what amounts to a new dimension in satnav: a whole new constellation in low-Earth orbit, bringing global coverage and most critically, a signal strength hitherto unknown to GNSS users. The satellite time and location (STL) has primary application in the timing realm, which is vital in many applications.
Higher in the sky, Europe’s GNSS satellites constituting the Galileo system officially began offering their services, and the multiple frequencies available here mean robustness, greater availability in obstructed environments, and — some say, though this is controversial — greater positioning accuracy, largely through more precise timing onboard.
Meanwhile, GPS World seeks a new defense editor for this column, and adopting the concept of “promoting from within,” now turns to its readership for interested parties to volunteer.
A New SatNav That’s Not GNSS
A strategic alliance announced on Dec. 15 between companies Orolia and Satelles includes will provide positioning, navigation and timing (PNT) solutions provided by the Iridium satellite constellation, independent of GPS/GNSS signals. The companies intend to provide PNT solutions to military, defense, government and commercial customers worldwide. Their new satellite timing and location (STL) service can supply much-needed robustness to GPS-dependent operations.
Orolia, the parent of GNSS-active companies Spectracomm, McMurdo, and Spectratime, has extensive experience in the defense realm. The company says it is #1 worldwide in the manufacture of military beacons outside the U.S. with a 60% market share, and #2 within the U.S., and that it is the first-ranked provider of Medium-altitude Earth Orbit Search and Rescue system (MEOSAR) worldwide. In partnership with Satelles, it will provide the STL service independent from traditional GPS and other GNSS satellite signals. STL is reported to be less susceptible to vulnerabilities such as spoofing, interference and jamming that are associated with GPS/GNSS — and the stronger signal penetrates buildings where GPS/GNSS cannot reach.
Iridium satellite, courtesy Iridium.
Based on the low-Earth orbit (LEO) Iridium satellite constellation, STL signals are up to 1,000 times stronger than GPS/GNSS; this signal strength, due in part to the constellation’s closer proximity to users, helps to prevent jamming and enables signal reach into buildings and other difficult locations. STL’s additional cryptographic security also enhances performance, productivity and security.
For further background on Iridium, see the June 2016 Defense PNT column by Don Jewell,“Iridium and GPS revisited: A new PNT solution on the horizon?”
Projected key applications and use cases include energy/utility grids, enterprise data networks including financial systems, maritime/aviation navigation, fleet/asset tracking management, search and rescue and data center management.
“The timing signal is very accurate and close enough to GPS for most timing applications, although the positioning accuracy is lower than what GPS users are used to,” said Orolia CTO Jean-Yves Courtois. “It is an augmentation for timing primarily, and secondarily for positioning.”
“In terms of timing accuracy, it provides on the order of tenths of microseconds in accuracy, and this covers a lot of timing applications, very familiar to us and to our customers. This is an ideal timing backup or augmentation of GPS. As number 2 worldwide in high-precision timing, we know this market and its applications very well.”
“In positioning it’s closer to fifty meters or more. Much better for fixed objects than for mobile objects. The more mobile, the faster the vehicle, then the lower the positioning accuracy. It’s not directly usable for GPS applications that require a few meters accuracy, but it can be associated with inertial navigation for much better results.”
“The signal is encrypted, so you have to subscribe to a service to receive a key, allowing access to the signal. Applications are developing based on equipment that will be STL-enabled. For the user it will be transparent. The user will have a different antenna.”
“We are also active in tracking and emergency location devices, where this is also of interest. It has some authentication capability, to guarantee that the person who accesses the signal is in the location that he pretends to be.”
Galileo, live at last!
Also on Dec. 15, the European Commission issued the Galileo Initial Services Declaration. The Declaration of Initial Services means that the Galileo satellites and ground infrastructure are now operationally ready. These signals will be highly accurate but not available all the time, since the constellation is not yet complete and users cannot always count on four satellites being visible at one time at all points on the Earth.
Galileo has a significant role to play in military operations. It adds multiple frequencies to the GNSS palette, important for resistance to jamming. It adds satellites, and will add more in the new future, very important for signal availability. And its Public Regulated Service (PRS) is specifically designed with special features for security, defense and military operations.
I attended a GNSS Symposium recently in Australia where an academic expert repeated the oft-made assertion that Galileo is the only GNSS that is civil-designed and civil-controlled. At which point an industry expert leaned over, grabbed the microphone and growled “Yeah, right.”
No matter how you look at it, Galileo add important benefits to GPS for the suitably equipped warfighter.
This Newsletter Enters a New Era
Beginning in January 2017, this Defense PNT newsletter will combine with our GeoIntelligence Insider e-newsletter to offer broad coverage of both hardware and software matters, driven by GPS/GNSS, and enhancing the capabilities of security, defense, military and other government forces. Readers of both newsletters will receive the new combined edition as a matter of course.
Many readers will know of the recent passing of Don Jewell, the longtime editor of Defense PNT. We must soldier on, and GPS World hereby extends an invitation to readers of this newsletter — many of whom, we know, are military experts in your own right — who may wish to volunteer to fill Don’s position. Please write to [email protected] to request details, and please provide a brief outline of your background and experience.
Until next time,
Happy Navigating.
