Solid state radomes compared, part 3 – Furuno checks in

Ben Stein

Ben Stein

Publisher of Panbo.com, passionate marine electronics enthusiast, 100-ton USCG master.

9 Responses

  1. Nick Fogarty says:

    HI Ben – Nice article , however you have one slight setup issue on the Furuno. When it is not raining, the rain clutter should be set to zero ( rather then auto – turn to auto with precipitation is around) – otherwise some small targets can get filtered – particularly in areas of high clutter like you are testing . This is probably closer to the Simrads specific Harbor setting. Also it looks like sea clutter is turned off on the Garmin unit? You are correct that the height can make a difference, I would also be interested if the Garmin firing back in to the front to of the Simrad and Furuno is causing them to have turn up the interference rejection. Look forward to seeing more shots.

    • Ben Stein Ben Stein says:

      Nick,

      The next time I’m out I’ll try the tests with rain clutter set to off. It’s hard to decide at what settings should be tweaked and what shouldn’t. I took a look at the TZT3 manual and it doesn’t suggest rain clutter be set to 0 when not in such conditions.

      -Ben S.

      • Ben — This is sound advice based on my experience with the DRS25A-NXT. In fact, I very seldom use the rain filter except in a torrential downpour. On the ARPA/”Fast Target Tracking” issue, I have the same experience when close to shore with vehicles moving about, They will get tracked and create some amount of clutter on the display. However, the tracking of targets on the water is truly outstanding, both in terms of the speed at which they are acquired and the accuracy of the speed an course data. When I compare the ARPA sped and course for a moving vessel with a Class A AIS transponder that updates very frequently, the ARPA and AIS data match very closely. My experience with Garmin MARPA was very different (in a bad way) as to both acquiring targets and accuracy of the vectors. I don’t have experience with newer Simrad or Raymarine radars to compare.

        • Ben Stein Ben Stein says:

          Good to hear the confirmation on rain filtering, I’ll do some testing with it off as well. I do expect that the target acquisition challenges I captured will fade as I get into more open water. But, even in my more confined water testing, I’d happily accept the visual clutter in exchange for the information it presents.

          -Ben S.

  2. Val Vechnyak says:

    Although I am in New Jersey, I’d be happy to weld that broken stainless bracket for you.

  3. Ben Ellison Ben Ellison says:

    I no longer have other radomes for comparison, but I’ve yet to see evidence that any competitor has equaled Furuno’s amazing Fast Target Tracking (ARPA) performance. As I wrote back in 2016, “NXT ARPA just works, rarely makes mistakes, and I find myself using it all the time”:

    https://panbo.com/testing-furuno-drs4d-nxt-solid-state-doppler-radome-radar-redefined-most-definitely/

    Eventually I bought that test DRS4D (and TZT2) from Furuno and I still use it almost all the time that Gizmo is underway. Mostly that means along the coast of Maine, where moving on-shore targets like Ben Stein is seeing around flattish Ft Meyers are rare. But I didn’t find such targets bothersome when I took the boat to the Carolinas either.

    The oddball targets I do sometimes see are nearby birds or Gizmo’s wake in flat water conditions, but I like to think of them as reminders that NXT is constantly looking out for moving objects possibly headed my way.

  4. Ben- I have been working on Marine Radar Detection Horizon calculations for a while now. I ran a model that adjusted the height of the radar by 1ft (0.33 meter) and observed a surprising amount of fading difference between 3.6 meters and 4 meter antenna heights, assuming a fixed target height of 10meters (thinking of bridges and tall trees on the islands etc). I’m not sure if you have seen plots of multipath fading when reflections from a flat surface (calm river surface) compete with direct reception at the radar antenna. The result is “constructive” and “destructive” interference that can amplify or null the amplitude of a radar detection (also impacts VHF radio communication etc). The flat calm and fairly conductive surface of the water can have a significant impact. So changing radar heights just 1ft can cause each radar to see the world a bit differently and it depends on range to the common target. I’m happy to send along plots and even copies of the formulas taken from Radar Design Principles / Nathanson / SciTech publications.

    I also concur that having all radars on at one time may have them responding to interference and may cause them to process targets differently when fending off other radars. I believe however that you have been placing all but one radar on standby and the UUT is the only one active.

  5. SV Confianza says:

    If I could trouble you to bring the Raymarine out for the next test, it would be appreciated! After the lightning strike, I installed all new raymarine gear. I know there are a lot of naysayers, but there were considerations when dealing with the insurance and our approved electrician.

    Would love to see the comparison out of sheer morbid curiosity. I am still struggling to get the quantum 2 settings the way I would like it.

  6. Jose Castro says:

    Hi Ben!
    I just back from Seattle, after upgrade 4 superyacht, upgrading the radar set up. Owner choose the Garmin fantom over the trustee Furuno used for years.
    I has the opportunity to try an old far 27 against the fantom and impressed me the easy to operate, the multiple functions and the capability to follow up other boat’s courses.
    I think the time to have 2 radars as coming to an end with the new solid-state radars with the new capability of have 2 screens with different ranges. Still waiting for a radar standard networking, common for everybody like nmea2k

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