Can someone explain radar to me please...
- Thread starter Sea Change
- Start date
boatmike
Well-Known Member
Not quite what you asked but I am not a fan of integrated systems. Radar in particular is a good candidate for a stand alone system and there is usually plenty of second hand raymarine and other kit on the market. I have an older Raymarine Pathfinder analogue colour set on my boat which is great but of course more power hungry than digital but then how often do you use Radar anyway? In my case its only in fog or bad vis when usually i have the engine running anyway. Don't buy a non colour set though as the colour versions are much clearer and have all of the functions of modern sets. A stand alone system in my opinion is also a good back up if the chartplotter goes down and because they generally get very little use you can usually buy a good one for a lot less than fancy new ones. If you have a bottomless wallet however feel free to ignore me!
PaulRainbow
Well-Known Member
Seriously ? A modern set is vastly superior to old analogue sets.
Almost no-one makes stand alone radar sets these days, they are generally MFDs. So why pay for one and only use the radar part of it ?
Sea Change
Well-Known Member
Our old radar was standalone. It was obviously better than nothing, but I think I can aim a bit higher.
We previously had AIS, radar, and charting on three separate screens, in three different places (chart table, companionway, helm). It was bloody awful. I'd very much like to see everything on the one screen, at the helm, with a repeater at the chart table. Doesn't seem too much to ask these days, even on a relatively modest budget.
We previously had AIS, radar, and charting on three separate screens, in three different places (chart table, companionway, helm). It was bloody awful. I'd very much like to see everything on the one screen, at the helm, with a repeater at the chart table. Doesn't seem too much to ask these days, even on a relatively modest budget.
lustyd
Well-Known Member
Agree. As i said earlier in the thread a standalone radar needs serious training to avoid radar induced collisions. Modern integrated sets don't have that issue and are entirely obvious in their use. Solid state radar also improved range both long and short while drastically reducing power consumption.
Old radar is as obsolete as CQR in my opinion and well worth the upgrade cost for anyone using their boat more than casually. For weekending i don’t think id even get a plotter these days.
Old radar is as obsolete as CQR in my opinion and well worth the upgrade cost for anyone using their boat more than casually. For weekending i don’t think id even get a plotter these days.
st599
Well-Known Member
I'm not sure it's solid state that has made the range detection better - small radars have been solid state for years - rather the move from measuring the time between a pulse and response to constantly sending a much lower power frequency sweep and measuring the returned frequency - you no longer have the issue of there being a deadspot until the radar switches from transmit to receive or the +/- half a pulse distance error.
One thing that is true though, modern radars don't work in the way the RYA tell you they do and have completely different issues to diagnose.
wonkywinch
Well-Known Member
How true, I complained to the RYA after my radar course that there was very little on chart plotter overlay interpretation rather it seemed to think I was studying to be an extra on the set during the filming of "The Hunt For Red October Part II" staring at some big orange washing machine.
lustyd
Well-Known Member
They’ve been developing an update for years but the reality is its just no longer necessary with modern kit.
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requiem
Well-Known Member
Ironically I tend to consider the plotter primarily a radar display, since primary nav is handled by phone/tablet/laptop.
st599
Well-Known Member
It's at least 7 years since instructors were told a new course was imminent.
I had hoped they'd go the way of US Sailing, Germany etc. and rather than force use of software written specifically for the course that's expensive to licence, they would use a software emulator that created NMEA sentences and could be displayed on your MFD or software plotter of choice.
lustyd
Well-Known Member
I don't think it’s a simulator issue. There simply isn't a reason to train with modern radar. Much as the RYA want to keep charging for courses, the outcome of a modern course would be unhappy customers feeling ripped off.
The modern version of that course is “look at your screen, the blobs show you where things are. Guess what they are and avoid”.
No need for plotters and chinagraph pencils or even dire warnings, its all just obvious. Hence the enthusiasm for new sets by those that have used them.
requiem
Well-Known Member
I'd be curious to hear more, as I've been fortunate to avoid encountering such issues.
Writing custom software would certainly explain a multi-year delay, but... to me that's just poor use of resources. Is such a NMEA dummy feed used elsewhere? Beck when I had instruction we simply sailed about and used the radar live.
lustyd
Well-Known Member
The simulator was used to demonstrate radar induced collisions so couldnt be done live sensibly. No longer necessary though.
dunedin
Well-Known Member
Raymarine plotters also have wifi and can be controlled by tablet etc
PaulRainbow
Well-Known Member
And phones.
Garmin does phones and tablets, either has full control, including autopilot.
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lustyd
Well-Known Member
I have to say i don't mind that my B&G doesn't allow autopilot control from the phone. Its a limitation but i can live with it. What drives me absolutely insane is that if the AP control is open, or if i accidentally touch it, the phone disconnects and i have to walk to the plotter to close it.
No two ways about it, thats some shitty coding and QA from people who have never been near a boat.
No two ways about it, thats some shitty coding and QA from people who have never been near a boat.
PaulRainbow
Well-Known Member
Although it does it, i don't use my phone, although it's setup with Active Captain in case i want to look at something in the pub or something
I have two plotters on the flybridge and they pair with two Android tablets at the lower helm. £240 worth of tablets and the free Garmin app, using the charts from my account, saves having to spend another £4K on plotters. Because i can control the AP from the app i can select a route or waypoint, hit the navigate option and i get a popup asking if i want to engage the AP. I can also just tap a spot on the chart, hit Goto on the pop up menu, then engage the AP. All from a tablet that cost £120, although they are on special at Amazon at the moment for £80.
You cannot do that with any other MFD/AP that i'm aware of.
requiem
Well-Known Member
Ah, thank you. I've started re-reading some old accident reports on the topic, and suspect that 1) a "see the blobs" approach is still inadequate for training, yet 2) the examples of radar-assisted collisions aren't caused by issues innate to radar, so trying to create a sim for them would be a wasteful bit of target-fixation.
lustyd
Well-Known Member
The radar assisted was a result of radar as it used to be. It was due to the screen always centring on the vessel. You could change course and without training never know if you'd made things better or worse. With chart overlay the blobs are static against the background where before they were always just relative to one another.
Dockhead
Well-Known Member
I would respectfully disagree with the notion that the "modern" use of radar is for a chart overlay, and all the more that chart overlays have eliminated "radar assisted collisions". That is certainly not true on board commercial vessels.
On board commercial vessels the predominant radar view for collision avoidance is North Up (AKA "Stabilized"), Relative Motion, so -- "the screen centring on the vessel". They do have radar overlays on their ECDIS displays, but this is used more for navigation.
On board yachts I dare say the predominant mode is Head Up, Relative Motion. That's how I use it.
Radar assisted collisions occur because of misunderstanding of relative motion, and simple failure to do a proper radar plot. The classic case is the MV Hual Trooper v. MV Fesco Voyager collision.
Relative motion is actually REALLY easy to understand, if you just think about it. Every sailor should buy a pad of radar plotting sheets and learn to do a proper radar plot without using any of the electronic aids. Then, you can throw away the plotting pad and simply set the EBL and VRM on a target of concern, and you INSTANTLY see whether you have a problem or not. If the other vessel walks down the EBL, it's a collision course. It's immediately visible. I prefer this to AIS, actually, it's my own primary means of understanding collision risk. I use AIS to confirm what I've observed by radar, and to get a calculation of CPA and TCPA without bothering with a full plot. But if I have to deal with a target which is not broadcasting AIS (military vessels, North Sea fishing vessels), I can still calculate CPA and TCPA, without AIS.
