Comments on: GLONASS Gone . . . Then Back https://www.gpsworld.com/glonass-gone-then-back/ The Business and Technology of Global Navigation and Positioning Fri, 22 May 2015 17:28:52 +0000 hourly 1 https://wordpress.org/?v=5.9.7 By: DFRC will hold CAMINO workshop about Cyber and Physical Security in September | DFRC AG https://www.gpsworld.com/glonass-gone-then-back/#comment-93967 Wed, 21 May 2014 10:49:23 +0000 https://www.gpsworld.com/?p=27601#comment-93967 […] shall be applied to them. An example of case history that matches the urgency is described here: GLONASS, the space-based satellite navigation system operated by the Russian Aerospace Defence […]

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By: Oops | Northing & Easting https://www.gpsworld.com/glonass-gone-then-back/#comment-46956 Tue, 22 Apr 2014 20:49:14 +0000 https://www.gpsworld.com/?p=27601#comment-46956 […] they say on TV, “but wait, there’s more!”  Back on April 1st the entire GLONASS system went wonky when bad ephemeris data was uploaded to the satellites. Ephemeris data is what allows each […]

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By: Ross Norsworthy https://www.gpsworld.com/glonass-gone-then-back/#comment-46608 Sun, 20 Apr 2014 19:00:35 +0000 https://www.gpsworld.com/?p=27601#comment-46608 In reply to John Schubert.

No, it does not have to be cat and mouse with jam and antijam, if we use the terrestrial eLoran solution, because this solution does not impose on any other system and it in itself is jam-resistant due to its extremely low frequency and high power.

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By: William K. https://www.gpsworld.com/glonass-gone-then-back/#comment-45215 Thu, 10 Apr 2014 01:09:14 +0000 https://www.gpsworld.com/?p=27601#comment-45215 Computer errors certainly do happen, with or without human involvement. Most code is produced by humans and therefore a bit suspect. And how did they survive without any nav aids?
Yes, e-loaran or else something better is what is needed for a backup. If our system were jammed, not taken down or spoofed, but simply jammed by a more powerful set of transmitters on the same frequencies, we could be in a big hurt, and only by shooting down the jammer could we fix it. Rotten nasty scenario, but it could happen and would not need that sophisticated hardware to do it. So we certainly need a non-gps alternate.

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By: John Schubert https://www.gpsworld.com/glonass-gone-then-back/#comment-45213 Thu, 10 Apr 2014 00:02:06 +0000 https://www.gpsworld.com/?p=27601#comment-45213 In reply to Ross.

There are anti-jam solutions, such as http://www.novatel.com/gajt/how-it-works/

Block IIF will have nulling antennas which can allow anti-jam increased capabilities. http://www.spaceflightnow.com/atlas/av039/gps2ffactsheet.pdf

Unfortunately, it’s always going to be a cat and mouse game between jam and anti-jam. The fact each satellite has to spread it’s RF across the entire width and height of the visible (from the satellite) Earth will have inherent hurdles.

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By: Ross https://www.gpsworld.com/glonass-gone-then-back/#comment-45205 Wed, 09 Apr 2014 21:20:43 +0000 https://www.gpsworld.com/?p=27601#comment-45205 In reply to Ben.

I support the comment “not just another GNSS” on the basis that one fatal failure mode that would take down all GNSS would be jamming, and when we have an economical jam-resistant terrestrial PNT backup that experts around the world have agreed and are proceeding with, namely eLoran, the USA would do well to invest in that.

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By: John Ingram https://www.gpsworld.com/glonass-gone-then-back/#comment-45180 Tue, 08 Apr 2014 23:10:33 +0000 https://www.gpsworld.com/?p=27601#comment-45180 I’m not working now, but still, don’t forget how to read a paper map.

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By: Ross https://www.gpsworld.com/glonass-gone-then-back/#comment-45177 Tue, 08 Apr 2014 22:33:52 +0000 https://www.gpsworld.com/?p=27601#comment-45177 In reply to Mike.

HR4005 (House passed, needs Senate approval) most recent legislation for US Coast Guard appropriations, will stop further destruction of Loran towers (only 8 are left out of 31) until eLoran is confirmed needed for GPS PNT (position, navigation and timing) backup.

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