Enclosed radars compared, including Garmin, Raymarine, and Simrad

Ben Stein

Ben Stein

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

17 Responses

  1. Allan Seymour says:

    Ben, nice comparison. Most of my radar usage is in fog and identifying other boats. Could you show us what other boats look like on these radars? Especially coming and going.

    • Ben Stein Ben Stein says:

      I certainly can. I was out during the week to do these captures and post-Ian boat traffic is well down. Getting out this weekend and getting some on-the-water time on a weekend day should give some good opportunities.

      -Ben S.

      • Ben Stein Ben Stein says:

        As I mentioned in my reply below to Mic, I’ve got lots of screenshots from a weekend day with plenty of other vessels on the water. I’ll crunch those and get part two published shortly.

        -Ben S.

  2. Howell Harold Alan says:

    Nice article. I think this also highlights the standard approach to turn it on, leave everything in auto and see what you see. As noted, each system is different and could likely do the job. The real gotcha for any user is to practice using the manual features, particularly gain in good weather. Then you will be confident in bad weather.

    I would love to see some of these scenarios in auto vs manual with a discussion of how much tweaking was needed to optimize performance. In essence how good is the auto on each vs real capability b

    • Paul s Inconiglios says:

      Yes, “I would love to see some of these scenarios in auto vs manual with a discussion of how much tweaking was needed to optimize performance.”

      I am far from an expert but would like a little insight to this.

  3. Hi Ben! Interesting stuff – though it poses more questions than it answers πŸ™‚ The “missing bridge span” issue is clearly vertical beam width – I suspect you could see the entirety of the spans from a distance off, and those sections disappeared as you got closer, because the beam was going under the bridge and not “painting” the span anymore. Whether this is bad or good depends, I suppose, on whether you need to know where the span is when you are close up or not.
    Modern radars do a LOT of signal processing between the receiver and the display — olde-tyme radars simply displayed everything they heard, and all the processing was up to the operator – some were really good at it, others not so much πŸ™‚ I suspect most of us are neither experienced or capable of the interpretation task, so the radar’s built-in processing is a necessary thing. But the cost of that processing layer is that anomalies appear – objects can appear and disappear from the display dependent on seemingly slight factors – minor changes in signal level, interfering signals, noise floor and so on. On an old radar, interfering radars are visible and distinct – but modern radars know what those signals are and suppress them – sometimes suppressing desired signals at the same time – but you would never know.
    Boat traffic? I was up at my brother-in-law’s place in Matlacha a couple weeks ago (helping pull wrecked porta-potties out of his bay) and it seemed like every boat on that area was out & about πŸ™‚

    Hartley

  4. Dan says:

    I would be interested in (1) pics (or short videos) during heavy rain, or close to heavy in the harbor and off-shore and your feeling of the workload using the three radars in conditions heavy rain and in night sailing. Perhaps when you estimate workload you can take estimate at what safe speed you can operate the boat and maintain situational awareness and if that is different for the three radars, or in some other manner judge how well you can maintain situational awareness using features for collision avoidance in a mix of boats with and without AIS. Lastly, if you could comment, on how well the products present radar targets that have an AIS return.

  5. Ben – I really compliment your effort here to get true side by side, simultaneous comparisons of these radars. The one condition that is very hard to control that is not expected by many when using Marine Radar is a secondary reflection from the sea surface under the main radar beam. This reflection causes a second detection of the target to be made at a slightly longer range than the direct path through the air. When both of these detections are received, they can cause either constructive or destructive interference that may either strongly enhance the detection of the target or strongly negate target detection. Small movements of the observing radar can cause the target to fade or appear on screen. This means that under some conditions, radar detection can appear to have a fading or building effect when the sea surface is relatively calm. The marine radar detection equation reflects this by including a SIN function of radar target height and radar height among other factors.

    All of this is by way of pointing out that some of the missing detections or enhancements you observed can be caused by radar location on the vessel, sea conditions and effects of the vessel structure on the antenna pattern. If the test boat was rotated a bit or moved longitudinally what is missing may appear and what is detected may disappear. All of this makes your challenge of offering performance comparison a difficult one.

    Other comments I could make would be to point out that any radar that you choose must be located as high on the vessel as possible and with the least amount of physical blockage in way of the radar as possible. I have seen many radars mounted in terrible locations with kayaks, dinghies, flybridge structure and even crew sitting locations physically blocking the radar system. ANY impediment to the clear view of the area surrounding the radar will cause loss of detection and odd reflection characteristics that will be hard to understand. If boaters thought of the radar as being a laser beam they would better understand why placing objects in way of the radar is going to prevent the laser beam from ever reaching a target.

    With regards to the Garmin radar performance in more open water and settings to “Offshore” mode, I would be concerned that the sea clutter / noise shown here is distracting and causes the operator to have to be “head down” while trying to determine if any of those dots is a target or not. From my perspective, while using land structures is convenient targets for comparison of performance, the real issue is marine target detections for safety. Land objects are useful to verify navigation but don’t help safety at sea nearly so often. The only exception being rocks / buoys etc. I much prefer using radar while being displayed as an overlay to a chart. This is the best way to quickly determine if targets are fixed hazards, navigation marks or potentially another vessel.

    An even better comparison would be to show the automated Collision avoidance displays that are provided by the radars and respective MFD. These collision avoidance displays can use both radar and AIS targets to warn of collision potential. Graphic images on my Raymarine display provide “keep out zones” that prevent collision potential based on target bearing and speed.

    One other good way to evaluate radar detections is to use a chart overlay with AIS vessels also plotted. We have seen AIS symbols for a large vessel that does not show a TOW that can be 600ft long that is following a large tug some 1000ft behind. Now only a radar will show you there are TWO vessels to worry about. In the Pacific Northwest we have a lot of commercial traffic that requires respect and planning.

    So, as I stated initially you have taken on a huge task. I compliment the level of effort and care in installation and image collection process that is not a simple thing to do! Great effort and article. Looking forward to seeing marine target detection comparisons as these are most valuable from my perspective.

  6. Rich West says:

    Nice work!

    I’ve been using a Simrad 4G radar for about ten years now and am pretty happy with it. I realize it’s getting to be time to think about what will replace this unit.

    We use our radar offshore 24/7 with a guard zone on to detect other boats. It’s important to us that there are a minimum of false alarms while catching everything real. Some of those screenshots look like there’s a pretty noisy signal that would cause a lot of false alarms.

    The other thing I’d be interested in is if any improvements have been made in MARPA on these units. Mine is pretty useless, showing rocks and islands traveling at up to three knots in random directions. It also doesn’t track a real target very well – losing it quickly.

    • abbor says:

      The 4G got an improvement in it’s MARPA functionality when the processor and OS were upgraded mid-life, so even the 4G got a slightly improved compared to your early unit. The ZoneTrack on dome Halao radards and the new Halo 2000 and 3000 is something compleatly different. Two zones can be defined, a sector or a circle or a combination. Both the inner and outer diameter can be set for both shapes. Up to 50 targets can automatically be acquired and tracked. Course and speed vectors and trails can be plottet for every target. NSX which Ben has been using for this review is lacking these vectors and trails, this will be added in a coming software release. NSS Evo3, Evo3S and GO series have this functionality. You can of course also manually select targets for tracking.The tracking is working very well, but I think a good heading compass is required for good perfomance. I have a HS75 satellite compass, but it works well with my Marteron SSC200 backup compass as well. Your 4G has 48 rpm max rotation and goes down to 24 rpm for A and B when running dual range. Halo has max 60 rpm, even in dual range mode. Very few false targets for any of my Halo radars, I have Halo20, Halo20+, Halo24 and the new open array Halo 2000 3′.

  7. John Midlige says:

    Hello Ben,

    I frequently ran a Garmin 18 HD at John’s Pass, Fl and used the trails on feature. I noticed you had it selected to off. In my experience it was an additional β€œalert” to moving traffic and objects detected.
    What are your thoughts about that feature and do the other systems have anything comparable?

    Thanks for an outstanding comparison. This type of work can’t be easy to do and Kudos for your professional unbiased review.

    John

    • Ben Stein Ben Stein says:

      John,

      All three radar units have echo trail features. In my near coastal testing I often find the trails provide a shadow or “fuzz” around almost all targets and can be a little distracting. I’m working on part 2 of the test and you will be able to see some of that fuzz in the dual range screenshots from the Garmin and Simrad radars.

      On a relatively clean scope, those trails can be hugely valuable to understand what a target has done over time and if there’s clear directionality, it’s clearly not moving, or perhaps is a transient return.

      -Ben S.

  8. Brendan says:

    Hi Ben, Great report for a challenging comparison. I guess the guys at Raymarine must have heard what you were going to say about the Doppler colours as my unit offers full colour mode on LightHouse 4 software!

  9. Mic Fite Mic Fite says:

    In the tradition of Ben E.’s past radar testing on Gizmo… Hats off for another great article, and service to the marine electronics community. I’ve been following marine electronics for twenty years and have read countless mainstream press articles on marine radars. Every one of them, if attempting to compare radars from the major manufacturers is simply a recitation of features gleaned from the marketing materials. Even in a well known marine publication that does not accept advertising, I found their radar shootout to be not particularly relevant.

    If anyone has published radar screen shots all taken from the same location at the same time I’m not aware off it. And combined with satellite photos, brilliant! Although they are all good radars, the subtle differences in these new solid-state radars certainly warrant investigation under different circumstances. I know this was a huge effort. Especially in midst of Hurricane Ian recovery. This very insightful. Thank you! Keep up the great work. I look forward to more results of your testing and learning about the strengths and weaknesses of each manufacturers’ product.

    • Ben Stein Ben Stein says:

      Wow Mic, what kind words. Thanks!

      I spent about six hours on the water over the weekend and took over six hundred screenshots trying to capture all the nuances I saw between the units. I did a bunch with doppler on and off, only one radar transmitting at a time, and every other permutation I could think of and test in the conditions I had.

      It’s winter in SW Florida, so we haven’t seen rain in a month or more, so I don’t have any inclement weather shots. But, I’m going to be pouring through the rest of the shots and creating more comparisons soon. So, look for a part two article before long. In the meantime, I’m knee-deep in a really cool small boat LiFePO4 battery.

      -Ben S.

  10. Dan says:

    I forgot to offer compliments in my post. Well done. I suspect the doppler coloring and other features of these radars have an effect on reducing the amount of time required to obtain situational awareness of the boats around the user. Potentially one of these radars excels over the others?

    In regards to choosing offshore mode, I would be curious why this needs to be a user option. I would think the various automatic noise filters can deduce if a boat is offshore or not, so then I wonder is the option there for some other reason and perhaps it just became clearer to give the control the onshore/offshore designation for some unrelated reason you could share with us?

  11. Sven says:

    Nice review – cool to see screenshots from the same spot/same conditions. Furuno not being present is a bit sad as they are so highly regarded.

    In addition to how it returns targets – would love to see an objective view on how ARPA works. With our Garmin setup – it’s nice in theory, but the MARPA fills up its targets, and then it is full, and I cannot manually add a target (ie the boat I see headed toward us) until it depopulates. Many of these MARPA targets are well on land so that makes the technology less useful. Though for a dome, marking boats is likely the primary need, as beyond that I would expect an open array to be better for birds/etc…?

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