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Tuesday, June 11, 2013

Detecting GPS/GNSS Spoofing using antenna articulation

There is a recent article out by Mark L. Psiaki, Steven P. Powell, and Brady W. O'Hanlon on GNSS spoofing detection, related to the specific possibility that the drone recovered by Iran was potentially spoofed into landing, allowing them to capture the drone.  The article also lays out a technological solution on how to prevent that from happening in the future; whether or not it actually happened in Iran which is still a matter of conjecture.  Technology simulating the spoofing capability was tested against a UAV helicopter (while hovering) in White Sands for simulation - but so was the possible solution.

The potential solution involved (in the prototype) articulating the GPS/GNSS antenna in a predefined motion that the spoofing system could not detect - allowing the augmented GPS/GNSS system to determine when the signal they were receiving was valid or not, by looking for regular perturbations of the signal caused by the induced motion. This appeared (according to the writers) to be an excellent way to detect GPS/GNSS spoofing in near-real-time.

While in the USA commercial and consumer tracking markets, we're more likely to run into low cost GPS/GNSS jamming systems, spoofing will likely be trending up in the near future.  What the military is encountering today, we in the commercial and consumer GPS markets are likely to encounter tomorrow.  As we continue to work with potential GPS/GNSS vendors we'll be asking about the future ability to include electronically synthesized antenna motion, as well as additional processing power for software radio based spoofing solutions; as well as the possible integration of inertial measurement unit (IMU) technology to help provide navigation holdover when the GPS/GNSS signal cannot be adequately discerned, or it is determined to be potentially inaccurate.  This may also be a practical solution for areas where electronic jamming is not the problem, but natural interference or degradation of the signal (such as obstructions in parking garages, tunnels, or due to multipath signals) is the culprit.