Tuesday, January 25, 2011

ICS-CERT GPS Outage Alert

This morning the DHS Industrial Control System Cyber Emergency Response Team (ICS-CERT) published an alert regarding an FAA notice about planned temporary outages of the Global Positioning System (GPS) due to DOD testing. “ICS-CERT is issuing this alert to Industrial control systems (ICS) owners and operators using GPS for timing reference or positioning data to alert them regarding possible intermittent GPS service during the testing.”

DOD tests will take place near Porterville, CA (January 16th through January 23, 2011. Affected Frequencies: M1575.42 and 1227.60) and Brunswick, GA (January 20 through February 11, 2011; February 15 through February 22, 2011.Affected Frequencies: not identified). Since both of these tests have been underway this is not a very timely notice. The alert indicates that the undescribed tests will last for 45 minutes followed by 15 minutes of ‘off time’.

Folks have to remember that the GPS system is a military system designed for DOD use, not civilian use. Why potentially critical systems were designed to use a GPS signal is completely beyond me.


Brad Calbick said...

Your criticism of the outage notification timing is spot on. However, I do question your last sentence. What is your proposed alternative to utilizing GPS for critical systems? I'm not aware of a solution that improves on the reliability and cost of GPS.

I would say rather that one should not rely solely on the GPS signal. There are reasonably inexpensive clock solutions available which couple the GPS signal with an internal high precision clock to provide a high accuracy time signal which can ride through GPS outages. Presumably there are similar systems available for positioning which couple the GPS signal with some sort of inertial navigation mechanism as well.

Suffice it to say, don't plan on giving up on GPS any time soon.

PJCoyle said...

For my response to Brad's comments see my blog post at:http://chemical-facility-security-news.blogspot.com/2011/01/reader-comment-ics-and-gps.html

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