The October readers poll asks “Are You Experienced?” It closes today. Take 30 seconds to give your jamming, spoofing, and/or other RF interference history, and enter a drawing to win $50 gift card.
The poll asks — and this is all it asks —
GPS/GNSS jamming.
GPS/GNSS spoofing.
Unintentional RF Interference.
RF interference from unknown source; unknown whether intentional or not.
None of the above.
Other, please specify.
I did experience interference one time in the area of Ann Arbor, Michigan. The result was “no service” for a distance of about 15 miles. After that there were no more problems.
Unintentional interference is a very common occurance when integrating GNSS modules onto a system motherboard. A common source is digital clock noise that either gets on the unregulated power supply supplying the RF chip or radiates through poor layout. Its solved by filtering power supplies, better layout, isolation cans over RF. It has a real impact on time to market for integrators, robs SNR, and even can cause accuracy issues for high sensitivity receivers.
In the recent years, most chips sets have integrated digital notch filters between the RF and Baseband that can attenuate multiple narrow-band CW interference. It gets back some performance and simplifies the integration layout concerns to a large extent.
As a chip designer, I have encountered unintentional jamming from aircraft transceivers and landing systems from an airport near our office that would block reception for a short time. We also had interference from medical equipment when our startup was above a medical office.
Personally, I have yet to experience a case of a spoofer or smart jammer.
But according to the experts like Dr Logan Scott, people are starting to use them when they can play with their GPS traces to avoid local fees or tolls. I can believe it.
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