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[TG] [TG11] Can Axiom Pro connect with two WiFi devices at once?
06-16-20, 07:52 PM
Post: #4
RE: [TG11] Can Axiom Pro connect with two WiFi devices at once?
Hello Marty,

How much attenuation you get through the deck depends on things like the lay-up of the deck and whether it's wet or dry (water attenuates radio signals quite effectively.) The GPS satellites broadcast from something over 30,000km away at around 25W so the power level is extremely low by the time it reaches your antenna: picture being able to see a 25W light from 30,000km away. It doesn't take much to block it, and the receiver needs to be able to see not just straight up through the deck but a number of satellites in different directions in order to be able to accurately triangulate your position: from where you want to mount the antenna, does it have just a thin layer of deck to look through in all directions, not just straight up? GPS antennas should always be mounted with a clear view of the sky.

To know for sure though, I would suggest this: connect everything together with the GPS antenna loose and run the ProAIS PC software. Compare the satellites in view, satellite signal levels and fix HDOP (a measure of accuracy) when the antenna is below-decks and then run it outside into clear air and look again. I suspect you will see a marked difference. If you have a poor signal level and sky-view then you will get a much less-accurate position fix or unreliable position fix, and it will be worst in the worst conditions (rain, heavy cloud cover, wet deck etc.) which is when you most want your AIS to be transmitting *accurate* vessel position information. See here for more information on fix accuracy.

Tom

Raymarine since 1999.
Interests: Diagnosis of problems in sonar/fishfinders, NMEA2000, ethernet comms, autopilots, thermal cameras
Location: Sydney, Australia.

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RE: [TG11] Can Axiom Pro connect with two WiFi devices at once? - Tom - Raymarine - Moderator - 06-16-20 07:52 PM

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