Axiom Side Vision

[gmckenzie]

Hi I have an Axiom 9 with RV-100 transducer with 3D imaging / Side image / down scan etc. latest software updated
I have noticed that my side imaging does not appear to scan at 180 Degrees as it is advertised, is there a setting to change this scan angle? It appears that I am seeing images that are picked up in my down imaging 60 deg. cone but not much outside that. For example when I drove past pilings for a bridge in 30-40 ft of water and I was about 8 ft from the pilings the scan only showed the bottom 2/3 of the pilings, and it didn't show the pilings on the other side that were about 50 ft away. I have attached a screen shot of what I am seeing. The transducer is mounted with a clear 180 Deg. view from it's mounting position, photo attached. The 2nd transducer is for a Dragonfly but it was turned off during this scan. I also noticed that as I got closer to the bridge pilings they would appear closer to the top of the scan view, but if this is truly 180 deg. scanning that shouldn't happen right?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum gmckenzie,

Scan angle cannot be changed, as it is based upon the fixed angle of the transducers elements. That said, we may be able to make some suggestions. Would it be possible to have you provide two additional photos of the transom with the engine / drive positioned in the full down position. The first should be a photo of the full back side of the transom. The second photo should be looking across the transom at the height of the transducer from the right side looking toward the engine / drive (again, the engine / drive should be positioned in the full down position).

[gmckenzie]

Please see attached photo's. I repositioned the transducers since I sent my original email, went out and re-tested and received the same results. The transducers used to be right next to each other, now they are separated. There is and always has been a clear visual line from the RV-100 transducer to the sides. When I did my side scan test the raymarine dragonfly was turned off to eliminate any possible frequency interference. The unit is advertised as 180 deg side imaging, but it does not appear that is what it produces, if that's the case I may want to return this unit as it is not working as advertised. I also attached a photo of the bridge columns that I scanned, they are about 3ft in diameter.

[Chuck - Raymarine - Moderator]

gmckenzie,

Thanks for including the requested additional photos. The latest transducer installations photos appear to show an optimal installation of the RV transducer. As the outboard/outdrive shaft is aft of the relatively narrow fore/aft beam of the RV transducer, you should achieve good viewing to both port and to starboard. With respect to interpreting SideVision imagery, the closest portion of the imagery displayed will be no closer than the transducer is proximate to the object within the water column. Within your screen snapshot, the image clearly shows the three bridge columns on the starboard side of the vessel. The closest portions of the returned bridge column imagery appear to be plotted approximately 11' from the centerline of the plot. Given that you had stated that you passed approximately 8' from the bridge columns and that the transducer is located approximately 3' inboard from the starboard gunwale, it would be expected that the closest point of the bridge column would appear approximately 11' out from the plot's centerline. I may be incorrect in interpreting the image, but there also appears to be sonar imagery from bridge columns on the port side, located approximately 75-80' from the centerline.

[gmckenzie]

Thanks Chuck,
My question / concern is why the columns do not appear to go to the top of the waterline (centerline of the screen), and why as I got closer to the columns did the ht of the columns appear to increase? To me that suggests that the Axiom / transponder is not reading at the 180 Deg angle but more likely something like 60 deg like the down vision.
Perhaps I am reading the side vision incorrectly, if so please help me understand why I am seeing what I am seeing, or not seeing in this case. I don't know if I attached a photo of the columns that were scanned but I have on this reply. As you will see they are significant in size, about 4ft diam. My interpretation of the way the side vision works is kind of like taking a flashlight view to the side from the transducer then take that view and lay it flat. So the black water column on the screen should show the columns going from the bottom to the top of the water column, and should show that whether they are 10 or 30 ft from the boat, vs getting shorter as I get farther away from them. I have asked others with a third party system if they see the columns go from bottom to top of water when they pass by bridge columns such as these and they say theirs does show it that way, so why does my system not show it that way?

[Chuck - Raymarine - Moderator]

gmckenzie,

Q. My interpretation of the way the side vision works is kind of like taking a flashlight view to the side from the transducer then take that view and lay it flat. So the black water column on the screen should show the columns going from the bottom to the top of the water column, and should show that whether they are 10 or 30 ft from the boat, vs getting shorter as I get farther away from them.

A. Realvision transducers essentially combine three 60 degree elements within a single transducer housing (one oriented to project from horizontal to approximately 60 degrees down, the second oriented directly downward (i.e. 30 degrees to either side), and the third projecting from horizontal on the opposite side to approximately 60 degrees down). Your interpretation of Raymarine's SideVision feature is indeed incorrect per my prior response. As indicated, the closest portion of the imagery displayed will be no closer than the transducer is proximate to the object within the water column. As the transducer was located approximately 3' from the gunwale and you stated that the vessel's gunwale was approximately 8' from the bridge columns, the closest point (i.e. the upper most part of the column near the waterline) extending into the center was rendered at approximately 11" to starboard within in the SideVision imagery. Accordingly, should the vessel be moved directly against the bridge columns, then it would be expected that the closest point (i.e. the upper most part of the column near the waterline) extending into the center will be rendered at approximately 3" to starboard within in the SideVision imagery.

[gmckenzie]

Hi,
I was playing around with the settings on my Axiom 9 with RV-100 and noticed that the scroll speed makes a huge difference in the clarity of the images using the side imaging. Is there a software update coming that will tie the scroll speed for Side imaging to GPS speed like the 3D imaging does?

[Chuck - Raymarine - Moderator]

gmckenzie,

Thanks for the feedback and for sharing your experience, as it may improve the performance of the imagery for other users as well. While further changes within sonar processing based upon input from the AHRS which is built into the RV transducers is being explored, Raymarine has not yet specified when when this will occur. That said, Raymarine is diligently seeking maximize the performance of sonar imaging in conjunction with the RV transducer.