[CA] [CA11] GPS SOG on Axiom Pro RVX

[Fish On]

Have an Axiom Pro RVX, and the SOG jumps around when running from 20knots, to 25knots which is my normal cruise.
I did not install an external antenna, and I do have a hardtop, that is triple fiberglassed, and an 8" thick offshore type I life preserver holder just above the Axiom Pro's.
Does this set-up affect the GPS SOG data?
Will the external GPS antenna correct this?
If so, which type works best.
Thanks!

[Chuck - Raymarine - Moderator]

Welcome back to the Raymarine Forum Fish On,

Q1. Does this set-up affect the GPS SOG data?
A1. Indeed, such installation locations would typically require and/or benefit from an external GPS sensor (recommended as a best installation practice) or external GPS antenna. If installing a GPS sensor, then the Raystar 150 GPS Sensor or AR200 Augmented Reality Sensor would be recommended. The Raystar 150 GPS Sensor or AR200 Augmented Reality Sensor would be configured as the Data Source for GPS, Date & Time, and Datum. If installing a GPS antenna, then a GA150 would be interfaced to one of the system's Axiom Pro RVX or Axiom XL MFDs, and that MFD would be then be configured as the system's Data Source for GPS, Date & Time, and Datum.

Q2. Will the external GPS antenna correct this?
A2. As the symptoms are suggestive on reduced GPS signal strength being received by the MFD's internal GPS sensor and reduced GPS signal strength can adversely affect position accuracy (and therefore COG/SOG accuracy), it would indeed be expected that position, SOG, COG, and the features dependent upon such data would improve with the installation of either of the options provided within the response to Q1.

[Fish On]

OK great. Going with the Raystar 150. Is the GPS Antenna; (Raystar 150) plug and play to the back of one of the Axiom Pro?
Or, does it get connected to the backbone?

[Chuck - Raymarine - Moderator]

Fish On,

The Raystar 150 GPS Sensor and AR200 Augmented Reality Sensor each feature a SeaTalkng / NMEA 2000 interface and as such are designed to be interfaced as spur to the system's SeaTalkng / NMEA 2000 backbone. The GA150 is designed to be interfaced to the corresponding socket located on the power/interface panel of an Axiom Pro / Axiom XL MFD.