Russian GLONASS Down For 12 Hours

An anonymous reader writes "In an unprecedented total disruption of a fully operational GNSS constellation, all satellites in the Russian GLONASS broadcast corrupt information for 11 hours, from just past midnight until noon Russian time (UTC+4), on April 2 (or 5 p.m. on April 1 to 4 a.m. April 2, U.S. Eastern time). This rendered the system completely unusable to all worldwide GLONASS receivers."

Comments

Down? Or encrypted?

[Anonymous Coward]

The system shutting down while still broadcasting "gibberish" seems awfully inconvenient. Sure they just didn't switch to encrypted transmissions?

Re:Down? Or encrypted?

[meadowsoft]

It is called selective availability. http://en.wikipedia.org/wiki/Selective_availability#Selective_availability My undergraduate thesis involved how to couple intertial senors using a Kalman filter to compensate for SA in GPS signals. Two years after my project concluded, the US disabled SA in GPS. I doubt that this recent "outage" was related to similar SA in GLONASS. Rather, perhaps it was indeed an encrypted transmission, or was based on a second independent synchronization signal only available to military assets used to put the scrambled transmissions back in the right order.

Re:How does this affect dual-system chipsets?

[Guppy]

Newer phones have location chipsets that support both GPS and GLONASS. Do they figure out automatically that the GLONASS information is bad and switch to using GPS exclusively?

To promote their system, Russia decided to make new smartphones without GLONASS support illegal in their country -- so major manufacturers added that capability to all their phones (since there is almost no additional cost to each unit, once the capability is designed into the chipset). Not sure about CDMA chipset, since there is no major CDMA networking in Russia.

Would be nice if we got Galileo GNSS and Beidou support too, but I'm not expecting it to happen unless they pull a similar stunt with their markets (well, China might).

   

Re:Warning Shot

[geekoid]

It was. The chain of event that follow the assassination were a pretty rapid and unlikely chain of events to have happened without that assassination.

If you are curious, reading the account of what was happening the day the Archduke Franz Ferdinand was assassinated is a comedy of errors.

It's also highly unlikely the WWII would have happened without WWI, since there would not have been the poverty and economic status Hitler used to gain power.