Technical Overview

GRIFFIN – Technical Overview

The GRIFFIN system comprises of multiple sets of RF signal reception nodes, referred to as Sensor Nodes (SNs), typically deployed surrounding secure facilities e.g. airbases, airports, ports and/or other critical infrastructure that needs to be protected, in addition to, one or more Central Nodes (CNs) that coordinate and control the GRIFFIN system. 

The GRIFFIN system consists of several Sensor/ Monitoring Nodes installed surrounding a regional area encompassing mission critical GNSS applications that require protection. Typically, several networked Sensor Nodes are installed around the perimeter, while controlled from a single central command location. This Central Processing Unit, coordinates each Sensor Node’s RF 360deg azimuth searching using both the electronically steerable antenna arrays and advanced signal processing techniques. When any RF interference or Spoofing instances are detected, the Central Processing Unit quickly tasks each remote Node to optimise beam forming for the required direction to intercept the target RFI signal(s), then collects and processes spectral data for geo-location function.

Using the combination of AOA data generated by each Node and combined TDOA processing of Node spectral data at the Central Processor location, any RFI source in the GPS frequency bands is quickly detected and geo-located to accuracies of a few metres within seconds. The location and type of interference is quickly and automatically passed to the appropriate authorities to deliver the required remedial action.

Multi element electronic antenna arrays for facilitating infinite combinations of rapidly switchable high gain (20+dBi) beams and/or deep nulls for complex directional patterns. The synthetic directional beams facilitate both intense focusing on the RFI targets and GNSS satellites during intentional signal acquisition. Then under different circumstances, deep nulls are used to reject GNSS satellites (considered unwanted background noise) while focusing on weak RFI targets at long distances.

  • Tuneable multi band coverage for all GNSS frequencies (GPS, GLONASS, Galileo, Beidou, etc.), with 20MHz to 30MHz coverage bandwidths while supporting high dynamic ranges.
  • Dual independent detection and geo-location analysis, incorporating both Angle of Arrival (AOA) analytics as determined by each of the Sensor Nodes, and combined Time Difference of Arrival (TDOA) signal spectral processing analysis as computed by the Central Node. Also includes automatic Sensor Node Array (3D orientations) and system calibrations.
  • Sub-Space Projection (SSP) processing technologies to facilitate very weak signal detection by removing the real GPS satellite signals (undesired noise) from the spectral data to lower the RF noise floor, optimising detection and geo-location of very weak RF threats at large distances (many kms) to within a few meters.
  • Enhanced simultaneous multiple JAMMER spectral characterisation, remotely determining each RFI signal source spectral type and RF transmission powers, including:
  • Narrow and Wide Band Noise sources
  • Swept/Carrier Wave (CW), (e.g. Personal Privacy Devices)
  • Pulsed CW, and, Comb/CHIRP Signals
  • Enhanced simultaneous multiple SPOOFER detection and geo-location capability. Leveraged from advanced antenna array directional patterns, SSP processing and normal signal correlation techniques multiple Spoofer detection and geo-location functions are easily accomplished for all the different GNSS signal types.
  • Fully automatic unattended operation and remote access support incorporating detailed remote supervisory displays of system performance and real-time spectral processing for each of the RFI threats. Also based on the determined RFI threat type, distance and RF transmission power, theoretical Area OF Influence displays are provided on Google Earth to assist an operator’s appreciation of the regional extent and effects to remote field GNSS users at that time.