On a pipelay barge, radio frequency interference to the vessel’s GNSS systems was reported by a surveyor. There was only one other vessel alongside. This vessel was contacted with a request to switch off any transmitting devices.
On that vessel, bridge systems with transmittal capabilities were switched off, and the pipelay barge GNSS functionality was restored. Vessel crew started troubleshooting, but the reason could not be identified and technical support from shore was requested.
What was the cause?
The shore service team used radio frequency (RF) detection and spectrum analysis equipment to detect and analyse RF signals transmitted by various sources, after which it was identified that the interference issue was caused by a factory-fitted SAILOR 150 Fleet Broadband which was not in use, but not disconnected.
The radio frequency interference came from a failed connector panel of SAILOR 150 Fleet Broadband System. This caused an outage of GNSS positioning systems for the surrounding vessels in close vicinity.
- Failed equipment can transmit a radio signal which can interfere with the communication or navigational equipment nearby;
- Check for any similar equipment onboard that is not in use, but not disconnected or powered down – removal may be worth consideration.
Members may wish to refer to:
- GPS antenna problems (2008)
- Potential interference of VHF-FM radio and AIS reception
- IMCA S 024 M 242 Guidance on satellite-based positioning systems for offshore applications
- Information Note id 1436 GNSS interference, jamming and spoofing [April 2019]
- Information Note id 1525 GPS systems – Warning of interference[October 2020]
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