Doppler radome testing tease: they’re all good

15 Jul

 

The picture tells much of the story (and you can click/zoom it much larger for the details). In rain and fog, the three 7-inch Garmin, Simrad, and Raymarine multifunction displays are each showing their respective solid-state Doppler-assisted radomes capturing well the complexity of Rockland Harbor moored vessels and shoreline while also automatically highlighting in red the most significant moving object, an incoming Maine state ferry also shown by AIS.

And I can assure you that the Furuno NXT radome that I was monitoring on a nearby iPad was doing just as good a job, arguably better. Yes, it’s taken me quite a while to properly compare the four Doppler radomes installed on Gizmo just as winter set in, but I believe I’ve done enough and the results are not surprising given lots of positive prior experience with the Furuno and Garmin versions.

Four Doppler radomes help find schooner Columbia in foggy Rockland Harbor

While it will take some time to sort through all the screenshots, I can report that the fairly new Navico Halo24 and Raymarine Quantum2 are also good radars, and that their Doppler motion-sensing features also have real value. Moreover, I have not seen any evidence to back the rumors about solid-state radar weakness in rain. In the full test report you’ll see all four radomes ignoring fairly heavy rain to see solid targets and also imaging wet squalls at some distance, even highlighting the ones that were headed my way.

The photo above shows all four radomes looking through the thicker fog that followed the early morning downpours, and I appreciated their help in getting another look at the mighty fishing schooner replica Columbia. I’d seen her the week before with all seven sails set and drawing as she took line honors in the Great Schooner Race, and if you’re cruising in Maine this summer I suggest finding her by AIS.

There weren’t many recreational boats out in Penobscot Bay during this 24 hours of wet SE winds, but I’ve become fond of fog for more than realistic radar testing. It can be grand, for instance, when a lift reveals a vessel like the Rockland windjammer Heritage hoisting her main topsail. Many more radar testing details to come.

Good radar and knowing how to use it can lead to moments like this

This article was syndicated from Panbo

Comments

  1. Panbo

    Thank you very much, Luis!

    Barry, did you notice “Testing Tease” in the entry headline? This was not even remotely intended as a full review. I also mentioned my favorite, though perhaps coyly. I think that the Furuno NXT is the best radome size-radar there is, including the other three brands of Doppler solid-state. (And the NXT has not changed substantially since I first reviewed it in August, 2016.)

    But that doesn’t mean everyone should buy a Furuno NXT. It and every other good radome is part of much larger networked system of navigation tools, boat monitoring, etc. so the decision is way bigger than radar.

  2. Barry Stott

    This article is frustratingly incomplete without a list of the SPECIFIC radar models you were testing. Are all four of these the newest and latest generation from each manufacturer? Also, are all four radomes the 24” round ones? It would be nice to see more photos of the specific domes mounted on your boat.

    It would be more helpful to display an initial harbor scenic photo including visible buoys and boats, then show a close-up shot of each radar display in order to make a better apples-to-apples comparison of radar resolution.

    Generally speaking, the two things that improve radar the most are antenna size and transmitting power. Granted, the newest aviation and marine radars do a pretty good job with small antennas and vastly improved digital signal processing of weak returns. Unlike aircraft, recreational boats are further hampered by having their radomes mounted at low “altitude” from 5 to maybe 30 feet off the water, limiting their ability to see over the horizon.

    Heavy rain will attenuate ANY radar signal which is why airline and fighter plane radars still use 8 to 100+ kilowatts of output power plus digital processing to punch through multiple rain cells that can easily block the weak signals from these latest low-power units no matter how good the processing. However, in a boat entering a fog-shrouded harbor while being pelted by just one local rain shower, the range is low enough that low power can usually get the job done.

    In my experience, overlaying live radar onto the chart plotter map display gives the best of both worlds, especially with the newest doppler techniques for displaying other moving boat traffic added in. This newest “trick” is still evolving, and I am not certain which manufacturer is currently leading the pack. Historically, Furuno made the best marine radars, but Garmin has been charging into the fray, and (patents be damned) everyone seems to be readily copying everyone else.

    Still, I yearn for a definitive (Practical Sailor?) Test Report that categorically says “At this time in nautical electronics development, ____X___ makes the best radar, and here’s why!”

    Sadly, most magazines are so beholden to their advertisers that very few are willing to make these definitive judgement calls. However, we all have to recognize that Numero Uno today doesn’t mean they’ll still be at the top when even newer stuff gets unveiled in Annapolis at the Sailboat Show this fall.

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