[ntp:questions] GPS Jammers in Use by Criminals - Warping Time for Fraud Suggested

Chuck Swiger cswiger at mac.com
Thu Feb 23 20:35:37 UTC 2012

On Feb 23, 2012, at 11:30 AM, Richard B. Gilbert wrote:
> On 2/22/2012 5:16 PM, David Woolley wrote:
>> An article in the Metro, the free morning paper on the London commuter
>> transport network, suggests that criminals may be using GPS jamming
>> equipment to warp the time on financial systems to allow the commission
>> of fraud.
> GPS is not the only source of time!

Certainly true.  ACTS phone dialup, NIST WWB/WWVB broadcasts in the USA, DCF77 in Europe, etc are other sources of time.

> In the U.S. 60 cycle Alternating Current is the standard and the source of time.  It's not going to give you the nanoseconds but very few people could even explain what a nanosecond is let alone needing nanosecond resolution.

In the US, the electric grid is supposed to be kept to within 10 seconds:


There are maps and tables showing the frequency corrections world-wide and for the US here (although some of the tables claim to be using sample data and not realtime measurements):



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