To Doppler or not?

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Bruce B

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So, American Tug is about to begin building our boat. We have picked colors, options, finishes, equipment and we are well on our way. One thing left for us to decide on is the electronics package. As I am developing a heavy bias toward Furuno, this question involves their radar.
Furuno has recently introduced a dome type solid state radar with Doppler technolodgy. That tech is not available in their open array Ultra High Definition Digitsl radar.

So all things being equal, say 4 kW units, which unit is going to offer the "best" performance? I like the idea of the Doppler where targets change color with relative direction but what is the downside? Doesn't the narrower beam width of the open array make for a superior signal and better target definition?

Just curious,
Bruce
 
New tech..always a gamble jumping on the bandwagon.

Broadband was touted for its great definition and low power...as other radar threads bring up....yes and no. I am happy that I stuck with the now many years old digital radar from Raymarine. Inexpensive, better than I was used to, clearly understand it's fine tuning and limitations, etc....

If doppler is clearly better and can do something old tech can't do, then it should be a no brainer.....but is it? I don't have any experience with it so my thrust is even if you don't get it, most radars on the market today (unless that model or line is having issues) are so superior to radar from just 15 years ago, fallback isn't a bad thing.

Things like ARPA are nice, but it is an automated feature, not a difference in return quality...so some improvements are only in add ons, not superior radar.

Reading the literature sounds impressive...if it works that we'll and is easy to get those features first time, every time.

Unless someone here you really trust has had one and cruised it for awhile, I would try and gets some real world hands on time as advertising definitely was off in my mind for broadband.
 
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Yes the open array should give you better performance.

But IMO, the reality is that these days the dome units are more than good enough for what most people are going to use their radar for.
 
New tech..always a gamble jumping on the bandwagon.

Broadband was touted for its great definition and low power...as other radar threads bring up....yes and no. I am happy that I stuck with the now many years old digital radar from Raymarine. Inexpensive, better than I was used to, clearly understand it's fine tuning and limitations, etc....

If doppler is clearly better and can do something old tech can't do, then it should be a no brainer.....but is it? I don't have any experience with it so my thrust is even if you don't get it, most radars on the market today (unless that model or line is having issues) are so superior to radar from just 15 years ago, fallback isn't a bad thing.

Things like ARPA are nice, but it is an automated feature, not a difference in return quality...so some improvements are only in add ons, not superior radar.

Unless someone here you really trust has had one and cruised it for awhile, I would try and gets some real world hands on time as advertising definitely was off in my mind for broadband.

So...
You suggest the tried and true. Am I correct in my assessment of open array vs a dome? I'm thinking the 4 kW open array, "older" technolodgy although it is more expensive. It's like twice the money.
Bruce
 
Yes the open array should give you better performance.

But IMO, the reality is that these days the dome units are more than good enough for what most people are going to use their radar for.

I will say that with the last Raymarine upgrade on our current boat, we had to replace the radome due to the fact that the old one wouldn't work with the new plotters. I remember liking the new digital HD color radar when we installed it.
It clearly worked better with fewer strange moments that the otherwise functioning analog unit that preceded it...

Bruce
 
Not really suggesting much more than if you have the chance, gets some real life hands on.

The broadband has great close in performance,average mid range and not so great distance performance....

So my question for the dpller is, are you giving anything up to go doppler?

As far as open array versus dome, I am with Capt Bill unless you are going bigger than 4KW. Even then, some domes are pretty big now, some as big as some open arrays...so look at bar length and the beam angles to compare. Even that doesn't guarantee better definition.
 
Simrad just introduced a sort of broadband/pulse hybrid radar called Halo that is touted as the best of both. Of course you would have to go with all Simrad electronics.
 
Not really suggesting much more than if you have the chance, gets some real life hands on.

The broadband has great close in performance,average mid range and not so great distance performance....

So my question for the dpller is, are you giving anything up to go doppler?

As far as open array versus dome, I am with Capt Bill unless you are going bigger than 4KW. Even then, some domes are pretty big now, some as big as some open arrays...so look at bar length and the beam angles to compare. Even that doesn't guarantee better definition.

Interesting. We've had more than our share of really foggy passages under radar guidance and when it is needed, you want everything you can get. I remember a particular trip coming back from Maine a few years ago. We'd left Tennants Harbor and made a run for the Cape Cod Canal. We transited the canal in a light fog and decided to push through to Cuttyhunk. As we chugged down Buzzards Bay the fog got thicker and thicker. By the time we got to Cuttyhunk at about 2 in the morning, we couldn't see the bow of the boat!

Now, when it is great visibility, I'd noticed that our plotter used to plot us over land when we were in the middle of the channel. It is a fairly narrow channel so we were well within the margin of error for WAAS GPS so it never really bothered me. Same thing happens when we enter our marina, the tracks show us as going across land sometimes...

Anyway, we know we can't go in strictly by plotter, visibility is ZERO and radar is working perfectly. I always tune my radar for peak performance too. Auto is great for a starting point but I am continually tweaking gain, sea clutter etc.

As we got to the Cuttyhunk channel entrance we slowed to a crawl. Target definition was barely enough to get the job done. That nice high rocky breakwater should have provided a great target (and usually does) but the rain and fog really was too much for our system. We figured it all out, very slowly and made our way in safely but I swore that if I ever had an opportunity to get a system that would work better under those circumstances I'd do it.

This new boat is that opportunity and I'm trying to learn as much as I can before making my decision...
Thanks,
Bruce
 
I am not a radar expert, but Doppler technology has been around for a long time, especially by the military.

The Furono, Nxt, Doppler looks very impressive, both in the articles I have read and feed back from the few users that have them.

It appears longer term, all radars for recreational use will be solid state, and the high output magnetrons will be phased out. I am sure there will be folks on here that will disagree with that statement.

I am doing an upgrade early Q1, and going with the Simrad Halo open array. I realize it has some shortcomings, like any system, but for a combination of short and long distance, low rad, and good user interface with the MFD, it's the package I like the best.
 
Kw for kw open array will always give you a better image due to the physical size of the antenna. Less back shadow. IMHO
 
For the kind of cruising we do on Magic, open array vs. dome makes no difference. We have had both on this boat. The dome we have now works perfectly fine for our needs and cruising area (Garmin HD). No matter what you chose, it will be outdated within a couple of years with a new "latest and greatest."

On our previous boat we had a Furuno 1721. It worked perfectly and always brought us home safely. It was installed in 1997 and was still in great shape when I sold the boat in 2011. Some say it is one of the best dome Radar units ever.

The difference between a $3,000 computer and a $1,200 computer is six months. Just sayin'
 
Back shadow means that the radar will show a elongated shadow when in fact the object is a round navigation marker. Or it will show two small objects close to each other when in fact it is one vessel or object.
 
In my teaching experience, often recreational radar owners really aren't very good with either adjustments or interpretation.

It is mostly practice but being shown the ropes opens a few eyes to some.

Bottom line, radar just needs to be able to show you whether there is clear watrcahead, or there is an object there. One, two, twenty two or the shoreline...... you really don't want to hit something no matter what it is.

It's radars that don't show you something out there that aren't acceptable.
 
Open array vs dome radar.

Open Array Wins.

http://www.thehulltruth.com/marine-electronics-forum/234018-open-array-vs-dome-radar.html

http://www.raymarine.com/view/?id=208

ImageUploadedByTrawler Forum1472659034.099390.jpg
 
There are always the exceptions to the rule..or apples to oranges arguements.

Broadband in close supposedly beats open array...so as I posted before...what do you want your radar to do best or what it MUST do in all circumstannces.
 
Personally, I'd call Furuno and chat with them about it. They are typically very straightforward. My opinion is that radar is the best piece of electronics to splurge a little on, if you plan on doing any cruising for extended periods of time. Next best is depth finders, VHF and then chartplotter.
 
Fletcher500;474931 I am doing an upgrade early Q1 said:
We installed a Simrad 4G Broadband radar a couple of years ago and are mostly very happy with it. It suits our needs perfectly as we cruise the BC coast which typically hems us in enough so that 15 NM out is rarely seen.

A couple of disappointments that we encountered after coming from a Furuno 4 KW system:

1) Radar does not keep a north up setting even though there is a setting for it. (it does so when used as overlay mind you.)

2) Radar does not have trails.

Simrad support told us that they were not going to fix those issues.

Those may or may not be issues for you, and/or they may be fixed in their Halo products, but I thought I'd give you a heads up.
 
There are always the exceptions to the rule..or apples to oranges arguements.

Broadband in close supposedly beats open array...so as I posted before...what do you want your radar to do best or what it MUST do in all circumstannces.

I will say...I have a crappy 15 year old Raymarine Pathfinder....I was surprised at how well it works. I have seen some extremely expensive set ups that were ok but I was shocked at the fact that they weren't that much better than mine.

THEN, I get on my buddy's boat(Hatteras 47 SF) and he has the latest and greatest Raymarine Digital broadband with 15 inch displays. I have to admit, I was blown away!!!!. We were painting cars on a bridge 5 miles away. I don't know how much better you need it to be at that distance. Not sure you could tell me that Broadband sucks at longer distances. I did not take him to task for any longer distance but the detail at 5 miles was amazing.
 
You asked about doppler, but getting mixed into the discussion is broadband vs pulse, along with small antenna/wide beam vs large antenna/narrow beam. Each affects performance in different ways, and of course they all inter-relate in various ways.

I think you can only do doppler with broadband, so they go hand in hand. And I'm pretty sure Furuno is the only company using doppler to assess movement and color targets according to danger level. To me this is a very useful feature derived from broadband, and highly applicable in the consumer market where people are not trained on radar operation and understandably need/want simple operation.

The other feature Furuno has recently introduced is their target analyzer. This is available in the NXT broadband radar, and also in their new dedicated pulse radars. It constantly analyzes all targets so when you click on one for ARPA, it comes up right away (or at least much faster than traditional ARPA). This too seems like a really useful feature, but note that it does not depend on broadband to do it.

If you bought a NXT radar you would get both of these capabilities, and personally I find that very compelling.

But, there are a few potential down sides to broadband that are typically swept under the rug. I say "potential" because I think, with varying levels of success, vendors do tricks to work around these inherent problems. But if I were evaluating the NXT radar, I would want to understand how these issues are handled. They are:

1) RACONs. Major buoys are often equipped with RACON and will return a strong, identifiable return. Broadband radars typically don't trigger RACON, so this navigation tool is rendered ineffective.

2) Interference from pulse radars. I found this to be a really serious issue with the Simrad 4G. When you get swept by a bigger pulse radar, it creates interference spikes radiating from your boat on your radar screen. This article shows an example screen shot of a mild case. The worst I encountered was a crossing ferry, and as the ferry got closer, my radar became increasingly unusable due to the interference. This is one of those dangerously escalating problems where the closer a boat comes the more you need your radar to track it, yet the more unusable the radar becomes. In engineering and math this is known as a positive feedback loop. The Tacoma Narrows bridge is a well know example of a positive feedback loop.

Anyway, I expect over time vendors will get better and better at working around these inherent broadband issues, but if I were considering the NXT radar, I'd want to hear Furuno's position on this, or better yet, find people using it and see what they say. My policy still holds that if a vendors lips are moving, they are spinning a story in their favor. The less charitable version is that they are lying.

A lot of people know that I've been very critical of Simrad's radars (pulse and broadband alike), but in all fairness I can't say that broadband technology is inherently good or bad or better or worse than pulse. It's what you do with it that counts. It has some inherent pluses and minuses, and everyone will have to decide what matters to them, hopefully based on factual info rather than repeated miss-information. But broadband or not, I think Furuno has some really useful new features, including at least one that is only possible with broadband and dopper.

Oh, and back in your original question you wondered about a 4KW dome vs NXT vs a larger open array. I think for typical trawler cruising a 4kw dome is just fine and will give you 90% of what a larger open array will do. So unless that extra 10% matters, I'd save the money and stick with a dome, either 4kw pulse or NXT.
 
I have the 4G now, and I agree with you. I also found some issues with painting targets at a distance, but I think my original install has some issues so I can't blame the radar. the Marpa function has been erratic, but that is a whole different subject. I think TT has documented these concerns well on his blog, and another website.

From what I have read about the new open array halo, and user feedback, The system is performing better than 4G. The Marpa function is still a ?, But I am hoping to get more data on that.

We installed a Simrad 4G Broadband radar a couple of years ago and are mostly very happy with it. It suits our needs perfectly as we cruise the BC coast which typically hems us in enough so that 15 NM out is rarely seen.

A couple of disappointments that we encountered after coming from a Furuno 4 KW system:

1) Radar does not keep a north up setting even though there is a setting for it. (it does so when used as overlay mind you.)

2) Radar does not have trails.

Simrad support told us that they were not going to fix those issues.

Those may or may not be issues for you, and/or they may be fixed in their Halo products, but I thought I'd give you a heads up.
 
In my teaching experience, often recreational radar owners really aren't very good with either adjustments or interpretation.

It is mostly practice but being shown the ropes opens a few eyes to some.

That is a valid Point. Unless the person providing feedback is commercial, a hard core cruiser with a lot hours, or a recreational boater but a solid radar background, then reports can be sketchy.

I run the boat quite a bit, at night, but still consider my radar skills to be B- at best.
 
We installed a Simrad 4G Broadband radar a couple of years ago and are mostly very happy with it. It suits our needs perfectly as we cruise the BC coast which typically hems us in enough so that 15 NM out is rarely seen.

A couple of disappointments that we encountered after coming from a Furuno 4 KW system:

1) Radar does not keep a north up setting even though there is a setting for it. (it does so when used as overlay mind you.)

2) Radar does not have trails.

Simrad support told us that they were not going to fix those issues.

Those may or may not be issues for you, and/or they may be fixed in their Halo products, but I thought I'd give you a heads up.

It just astonishes me, though it probably shouldn't, that a company so blatantly sells a product with features that don't work and where they have no intention of ever delivering on it.

In my time as the CEO of a soon-to-be-public company, we always followed the FASB (Financial Accounting Standards Board) accounting rules for public companies. The last thing you want to do as you are getting ready to go public is have to restate your earnings because you have been playing it fast and loose. And even if you are private, any reputable accounting firm won't sign off on an audit that doesn't meet FASB rules.

A big part of the FASB rules has to do with revenue recognition. In a nut shell, you can't recognize revenue for something until you have fully delivered on it, even if you have been paid. For services, you can only recognize for the portion of the service actually performed, so if you are 3/4 of the way through a job, you can take 3/4 of the revenue. The balance is deferred revenue that might be later recognized, or might be lost if you don't deliver.

With products, you have to deliver the whole product. Places where you get into trouble are:

1) Starting to sell a product before all the advertised features are complete. Simrad does this on a regular basis. The NSS and NSO were sold without properly working structure scan. The Halo radar was sold without MARPA. The TX open arrays are sold with a park angle feature that doesn't work and that simrad says can't be implemented given how the radars work. I now learn that North Up and Echo Trails don't work and won't be delivered. In these cases, you have sold people a bill of goods and not delivered on it. People bought based on what you told them, and because you didn't deliver that can return the product for non-performance. So from an accounting perspective, that revenue isn't irrevocably yours, so you can't recognize it until you have fully delivered.

2) Announcing new features to be available in a software update. Simrad sold MFDs with the promise that they would support Forward Sonar Scanning, to be supported in a future release. Same with MARPA on the Halo Radar. Now you have enticed people to buy your MFDs with the expectation that it will do something in the future. If you never deliver, customers can demand their money back on the MFDs, and actually the whole system. Accountants see this as revenue that is not irrevocable, so won't let you recognize it.

Based on this one could argue that Simrad shouldn't recognize any of the revenue for any MFDs, or any 3G or 4G radars. Same with the TX radars. Halo radars too if the issue extends to them. And there is an argument that all other system parts inseparably linked to the MFD and/or Radar should not be recognized as well since you bought them as a result of your decision to buy the MFD and/or Radar. I know our accountants (Price Waterhouse) would never have signed off on it.

If they were a public company in the US (SEC regulated), they would probably all be in jail.
 
From what I have read about the new open array halo, and user feedback, The system is performing better than 4G. The Marpa function is still a ?, But I am hoping to get more data on that.

BTW, just the other day I posted a request on The Hull Truth for Halo radar owners to do some testing of MARPA and post pictures or videos of the results. Several people over there claim to have them. It would be good to see how much it has improved, other than Simrad saying "it's much improved". If you know anyone who has one, I'd be happy to provide instructions on how to test it. It's pretty easy.

The big risk is that once someone has bought something, they are greatly inclined to favor that decision. So I might just get people posting pictures of MARPA working correctly rather than trying different things for a while looking for incorrect results. It's not wrong 100% of the time, so it takes some effort looking for the problem, and owners are likely to turn a blind eye towards that. It's human nature. But hopefully some objective results will surface.
 
In my teaching experience, often recreational radar owners really aren't very good with either adjustments or interpretation.

That is me. I am good at neither so my Radar is better than I am. I hope that I will get better at interpretation over time.
 
To me north up on a radar only makes sense when used on a chart plotter overlay that is also north up. Sounds dangerous otherwise. When I am at the helm, I prefer looking straight ahead!
 
To me north up on a radar only makes sense when used on a chart plotter overlay that is also north up. Sounds dangerous otherwise. When I am at the helm, I prefer looking straight ahead!

Agreed!!! My whole world is north up!!!
 
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