Disabling GPS Interference Devices
In the fast-paced world of broadcasting, the risk of GPS jamming has become a growing concern for broadcasters operating in turbulent regions like the Middle East and near Russia. According to a report in the July/August issue of TVBEurope, this issue is particularly pertinent for satellite-related broadcast services.
One solution to this problem is the use of the LT4670, a sync pulse generator (SPG) that can use satellite navigation systems including Galileo (EU), BeiDou (China), GLONASS (Russia) and QZSS (Japan) in addition to GPS. This multi-GNSS capability brings robustness to the setup, as jamming all GNSS simultaneously is harder than jamming one of them.
The LT4670 also uses an internal Oven Controlled Crystal Oscillator (OCXO) that can frequency- and phase-lock to a GNSS, providing reference signals based on the internal OCXO if connection is lost. In such events, broadcast setups can establish connections and achieve synchronisation with GNSS before the event.
Broadcasters can mitigate GPS jamming threats by acquiring an SPG with multiple constellation GNSS receivers, such as Leader's LT4670. Another feature that can benefit broadcasters is 'Slow Sync', which reduces the shock when synchronisation is re-established based on stay-in-sync.
Effective strategies for broadcasters to mitigate GPS jamming risks in live and remote production include a combination of technical, operational, and procedural measures.
- Use of Anti-Jamming Technology: Employ directional or controlled reception pattern antennas (CRPAs) that dynamically steer nulls to suppress jamming signals and maintain GPS reception integrity.
- Multi-Sensor Cross-Checking: Integrate alternative navigation and timing sources such as Inertial Navigation Systems (INS), local timing references, or DME/DME triangulation to validate GPS data and detect anomalies caused by spoofing or jamming.
- Operational Vigilance and Situational Awareness: Continuously monitor GPS signal quality for discrepancies or sudden position/speed changes that indicate jamming or spoofing.
- Fallback to Conventional Systems: Plan for contingencies by using conventional synchronization and navigation aids when GPS is disrupted.
- Prompt Incident Reporting and Communication: Maintain close communication with relevant authorities to receive timely alerts about signal disruptions, and report incidents promptly to enhance collective situational awareness and coordinate mitigation efforts.
- Use of Advanced Firmware and Detection Tools: Deploy GNSS resilience technologies and interference mitigation firmware like NovAtel’s GNSS Resilience and Integrity Technology (GRIT), which can detect and mitigate spoofing and jamming before they impact final timing and positioning solutions.
If all SPGs have previously locked to GNSS, they will transition into 'Stay-In-Sync' or holdover mode when GNSS is lost. This functionality is known as 'Stay-in-Sync' mode or PTP Clockclass 7.
Broadcasters operating in turbulent areas should not overlook the importance of these measures. GPS jamming can disrupt transmission site synchronisation, affect transport stream timing in SFNs, and impair remote production tools. By adopting a layered approach combining hardware anti-jamming measures, alternative timing/synchronization sources, operational procedures for monitoring and response, and advanced detection software, broadcasters can effectively mitigate GPS jamming risks during live and remote productions.
Data-and-cloud-computing technology can be utilized to develop advanced firmware and detection tools, such as NovAtel’s GNSS Resilience and Integrity Technology (GRIT), which can detect and mitigate GPS jamming before it impacts final timing and positioning solutions.
Effective data-and-cloud-computing strategies for broadcasters to mitigate GPS jamming risks in live and remote production include a combination of hardware anti-jamming measures, like directional or controlled reception pattern antennas (CRPAs), and software solutions that enable real-time monitoring and response to potential threats.
