[CA] [CA11] EV-1 Cycles 360 Degrees (Even While Docked)

[dlane1181]

Thank you for the insightful commentary. Both of our Axiom MFDs are mounted without unobstructed views of the skies overhead. However, although the reported HDOP is high (presently 1.2, down from 1.5 a day ago), we already have an external GPS sensor mounted atop the main cabin with an unobstructed view of the skies overhead. (It is not a Raystar 150, and I cannot tell what make or model it is.)
Until recently, though, our nav suite worked as advertised and we had no issues with erroneous COGs whether underway or stationary.
I suppose our GPS sensor could be failing, or we have a faulty connection between the GPS sensor and the MFD data master. Do you have any troubleshooting suggestions for determining either? I'll try and trace the line from the sensor to the MFD, weather permitting.

Here is additional information for the conversation as of 12:00 UTC, 17 December:

It's a bright, sunny day today and HDOP values have ranged from 0.7-1.3. The COG continues to cycle through 360 degrees on the MFD itself despite no way on; however, no COG is displayed (--) on the i70 instrument, whereas it was cycling on this display previously.

We traced the GPS Sensor lead from the cabin roof to our Raymarine E32158 AIS transceiver. All connections and contacts appear intact, and we noted no kinks in the coax cable connecting the two components. The AIS transceiver is integrated into our Raymarine nav suite via a Raymarine HS5 Network Switch.

Although possible, it seems unlikely that the GPS Sensor connection is faulty.

Thank you for your any additional technical troubleshooting tips you can provide.
Thank you.