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09 5 2016

Testing direction finder at GPS Jamming Trials


In August, the NCI Agency participated at the annual navigation warfare (NAVWAR) trial in Sennybridge, Wales, United Kingdom, hosted by the UK Ministry of Defence.

For the entire duration of the trial, broadcast authorities in the UK grant permission to deploy jammers to allow testing of GPS-equipment under realistic jamming conditions — this was a rare opportunity given the tight regulations! The trial, mostly supported by UK participants, was opened this year to attendees from NATO agencies, so the NCI Agency took the opportunity to test the GANDALF Mk II system.

About GANDALF Mk II system

"GANDALF" is an acronym for "Ground-based Asset by NCI Agency for Direction and Location Finding" and is an experimental system based on relatively low-cost components. The operating principle is based on measurements to allow estimation of the jamming signal's Direction of Arrival (DoA). Doing this for multiple locations allows the identification of a jammer's position.

The receiver system employs software-defined radios, an in-house constructed antenna array and implements various algorithms to perform the DoA estimation. Moreover, GANDALF Mk II provides a powerful tool for the Electronic Warfare (EW) operator to characterize the precise type of jammer signal.

These activities are of great value to help maintain the Agency's technical expertise and keep abreast of new developments in radio software and hardware technology. Further, this experience is of direct benefit to the Agency role as 'smart buyer' in support of specialized procurement projects.

Global Positioning System

The Global Positioning System (GPS) is a satellite service critical for navigation on the ground, sea and in the air. Civil aviation, maritime traffic and the TomTom boxes for cars all employ GPS. In addition, the timing GPS provides is essential for, e.g., synchronisation of mobile phone base-stations and computer networks. For this reason, the GPS frequency band is tightly protected around the world from interference or jamming.