RADAR - manual or auto tune? Chart overlay?

[mvweebles]

Recent thread on radar in fog got me thinking about how people use modern RADAR. In the CRT days, tweaking the tuning was a regular activity - auto tune on modern sets is much better. But is it good enough?

For people who regularly use their radar, how many use manual tune functions vs auto-tune? How many prefer chart overlay vs separate radar and chart displays? Are the answers situational dependent - perhaps there are weather conditions where auto-tune doesn't achieve satisfactory results?

Peter

 

[ScottC]

Prefer chart overlay. Auto-tune is the default, but then I experiment & tweak, based on the situation and the amount of clutter, as I only agree with auto-tune results ~50% of the time.

 

[O C Diver]

I prefer manual tune. Usually run my radar to display 2 ranges. Each range has its own tune, gain, rain and sea clutter. It's pretty easy to make minor adjustments in changing conditions. Sometimes I will tolerate a little more sea clutter to get a solid image on a small boat or buoy. Computer tuning and auto clutter reduction can either be to sensitive or not enough.

I prefer not to use radar chart overlay. Having come from decades of using paper charts, my brain thinks in North Up (never turned a paper chart to figure which way I was going). Having 3 multi function displays plus a computer screen for navigation, it's easy to display what you want and scan between. Prioritizing is also important, most times one is more critical than the other. When chartering, coming out the inlet in the fog, after clearing the inlet buoys, targets are my only concern until I reach the seabuoy. While the radar is running on a separate screen, on a clear day, cruising a narrow channel on the AICW is all about navigation markers. In both cases, I don't need superfluous information.

Ted

 

[twistedtree]

I start with auto tune, but often tweak from there.


I used to overlay radar on my charts, but found two interesting things along the way.


First is that too many times I found confusion between the radar overlay and the underlying chart. Noise in the radar return was obscuring anything red on the chart, and making it hard to read depths and other notation. Too many times I found myself missing something because I thought it was a radar return when it was a chart feature, or vice versa. When the displays are separate, it's easier to compare the two and know for certain what you are seeing.


Second is that I realized my desire to overlay radar was really a crutch because I wasn't very good are reading and interpreting the radar return. With the radar co-displayed with a chart, it was much easier to correlate the two. But over time I got better are reading the radar return, and could more quickly and dependably identify what I was seeing, and correlating it with the chart. It was simply a matter of practice and experience. So I abandoned the crutch, and permanently separated them (my last and current boat aren't even capable of overlay), and have never gone back.


Other than visually identifying things on the radar, there are a few other tools for checking it against your chart. Bearing lines and range rings, or even just a cursor placement on your radar will locate something both by range and bearing, as well as lat/lon (assuming you have your electronics all hooked up correctly). You can then do the same on your chart to correlate against your radar view.


Target tracking is also incredibly useful. Again, when properly set up, anything you track with ARPA on your radar will show up as an icon on your plotter. Those are inherently the things you care about the most, and they, and only they take up space on your charts. It's kind of the ideal filter for what portion of your radar return to show on your chart. Target tracking is also useful for picking out returns that are buoys vs other boats, as they are sometimes hard to distinguish when close together.

 

[mvweebles]

Ted - brings up another question: heads-up; course-up; or north-up? Radar was only heads-up until fairly recently of course. Heads-up means the image isn't stabile so is probably the least preferred. North-up doesn't require NAV be engaged so I understand that but is not nearly as intuitive for me, and certainly not for crew. I do like the lollipop display of a way point on radar. In a channel, I'll lay the mark between channel markers.

I find chart overlay distracting. I will sometimes toggle to it to verify a radar target but prefer to keep the "should be there" (chart) separate from the "is actually there" (radar).

My old Furuno 1721 CRT radar died just before leaving San Francisco for Mexico last year so a did a hasty install of a Simrad 4G digital system. I didn't get around to learning it much, but auto tune seemed to be much more reliable than the old stuff, even the NavNet2 systems of just a few years ago.

Thinking about it, there was a recent thread on how single handlers sleep. A very common response is AIS and radar zone alarms. Assumes radar is properly tuned. My observation is less than 20% of boaters know how to tune a radar - many over-tune to remove clutter which also removes targets and any associated alarms of course. Wonder if that's still a problem with modern digital sets?

 

[mvweebles]

I start with auto tune, but often tweak from there.


I used to overlay radar on my charts, but found two interesting things along the way.


First is that too many times I found confusion between the radar overlay and the underlying chart. Noise in the radar return was obscuring anything red on the chart, and making it hard to read depths and other notation. Too many times I found myself missing something because I thought it was a radar return when it was a chart feature, or vice versa. When the displays are separate, it's easier to compare the two and know for certain what you are seeing.


Second is that I realized my desire to overlay radar was really a crutch because I wasn't very good are reading and interpreting the radar return. With the radar co-displayed with a chart, it was much easier to correlate the two. But over time I got better are reading the radar return, and could more quickly and dependably identify what I was seeing, and correlating it with the chart. It was simply a matter of practice and experience. So I abandoned the crutch, and permanently separated them (my last and current boat aren't even capable of overlay), and have never gone back.


Other than visually identifying things on the radar, there are a few other tools for checking it against your chart. Bearing lines and range rings, or even just a cursor placement on your radar will locate something both by range and bearing, as well as lat/lon (assuming you have your electronics all hooked up correctly). You can then do the same on your chart to correlate against your radar view.


Target tracking is also incredibly useful. Again, when properly set up, anything you track with ARPA on your radar will show up as an icon on your plotter. Those are inherently the things you care about the most, and they, and only they take up space on your charts. It's kind of the ideal filter for what portion of your radar return to show on your chart. Target tracking is also useful for picking out returns that are buoys vs other boats, as they are sometimes hard to distinguish when close together.

Good post. Question for you TT: guessing you do some distance runs. How do you manage radar tuning for crew? Are you comfortable they are knowledgeable to tune, or do you leave in auto? What other console changes do you make for crew watch?

Peter

 

[ranger58sb]

auto tune on modern sets is much better. But is it good enough?

For people who regularly use their radar, how many use manual tune functions vs auto-tune? How many prefer chart overlay vs separate radar and chart displays? Are the answers situational dependent - perhaps there are weather conditions where auto-tune doesn't achieve satisfactory results?

I start in auto-tune, and tweak as necessary. Most of the time, I've only needed to deal with a bit of clutter...

I'd like the have the ability to overlay the chart... occasionally... but I didn't have that... and would prefer to work without the chart overlay 99% of the time anyway.

Ted - brings up another question: heads-up; course-up; or north-up? Radar was only heads-up until fairly recently of course. Heads-up means the image isn't stabile so is probably the least preferred.

Huh?

FWIW, I find head-up on the radar intuitive, the other options... not.

OTOH, I prefer north-up on the chart (whereas my chief navigator thinks better using the head-up display).

-Chris

 

[Portage_Bay]

I manually tune, though I've not used the newest gear. Perhaps auto tune is better now.

I keep radar and plotter displays separate. When I first saw plotter / radar overlay I thought it pretty slick but quickly went back to separate screens. Just too much information on one display, things get lost.

The plotter is always north up. For the radar it depends on where I am.

• On open water north up. My preferred mode, nearly 100% of the time.
• Entering a harbor, running a narrow channel etc heads up.
• Sometimes, rarely, when on a steady course in a congested area course up.

When standing watches I let each watch choose what they are more comfortable with. I do require that at the change of watch when you are relieved you inform the oncoming watch which mode the radar is in.

 

[mvweebles]

I start in auto-tune, and tweak as necessary. Most of the time, I've only needed to deal with a bit of clutter...

I'd like the have the ability to overlay the chart... occasionally... but I didn't have that... and would prefer to work without the chart overlay 99% of the time anyway.




Huh?

FWIW, I find head-up on the radar intuitive, the other options... not.

OTOH, I prefer north-up on the chart (whereas my chief navigator thinks better using the head-up display).

-Chris

Could be semantics. My meaning of heads up vs course up: Heads up swings with wherever the bow is pointed and can swing quite a bit depending on vessel and sea state. Course up stays pointed at the way point and does not swing.

 

[psneeld]

Isn't Radar generally head up unless gyro or rate compass augmented?

Like recreational RADAR was for decades?

My RADAR lubber line is always what is off the bow.

It is essentially all I have ever used except on USCG cutters or a delivery now and then.

 

[mvweebles]

Isn't Radar generally head up unless gyro or rate compass augmented?

Like recreational RADAR was for decades?

My RADAR lubber line is always what is off the bow.

It is essentially all I have ever used.

My old Furuno 1721 CRT was the gold standard for years on <60 footers it seemed. It had some sort of course dampening so it didnt swing much. Had MARPA that wasn't very replable though it was helpful to at least tag a target even if it disappeared. I think it dated from around 1990. Was a good set and I was sorry to see it die.

On the Simrad 4G set at least, to get MARPA and I believe chart overlay requires a rate compensated compass be installed. Cheapest way to get one of those is to buy a A/P driver package. And so it goes....

I find course up much easier to interpret, especially if I'm triangulating visual sight lines for a target. Somehow, targets - especially vessels - always seem like they are at a different angle than shown on the radar.

 

[High Wire]

My first radar was manual tune but with with a tune indicator and a separate knob. Very easy to operate.
My next radar was older with manual tune and up/down push buttons and no tune indicator. Awful to operate. Complete pita.
My next two radars were auto tune with no manual tune capability at all. Very easy but I always wonder if it is peaked properly. Ya just gotta believe I guess.
I’ve tried overlay on my current Garmin xhd24. It makes the chart hard to read and the radar is cluttered even worse. Fortunately the display can be split side-by-side, which is my goto combination.
Head up for the plotter keeps it pretty close to the radar display as long as the ranges are similar. Not perfect but close enough.

 

[psneeld]

Sure the different tools help in some situations or personalities as we all like different things...just was wondering why heads up was considered a recent innovation?

Like I mentioned....for years only commercial or the boater willing to spend the money (which most didn't or could) had units capable of more than heads up.

 

[mvweebles]

Sure the different tools help in some situations or personalities as we all like different things...just was wondering why heads up was considered a recent innovation?

Like I mentioned....for years only commercial or the boater willing to spend the money (which most didn't or could) had units capable of more than heads up.

Agree. Heads up is normal. Everything else requires some sort of interface which, as you state, wasn't an economical option until 20 years ago or so. Just wondering what people run in.

I would think north up on radar would be awkward to learn. Has benefit of aligning to paper chart so maybe useful on occasion. But I'd find it difficult to run in as a regular practice.

 

[rslifkin]

I'm not a fan of overlay, mostly because in my mind, radar functions as heads up, charts need to be north up (trying to read a chart that rotates drives me crazy).

 

[MYTraveler]

I am in the chart north up, radar heading up group, and really couldn't imagine doing it any other way. On rare occasion, perhaps navigating a narrow channel in the fog, I will overlay, but when I do, the plotter stays north up.

As for auto, I leave most of the radar adjustments in auto mode. The two exceptions are that I don't activate rain clutter reduction unless it is raining (on me), and I manually adjust the gain.

 

[ScottC]

Heading-up.

 

[psneeld]

I used to be chart North up...but running narrow back channels at speed at night.....slowly got me used to head up.

My radar is only head up.

So when running the ICW, I have both on heads up, same range with same distance range rings. In less than a second I can match up targets with charted objects. Has worked for me many a mile in waters that seems like many wouldn't do in fog.

 

[Fletcher500]

I also like Heads up.

I use Chart Overlay near the coast when there is not much traffic around, but as others have indicated, I also think radar only display is best because targets can blend in with the chart plotter background.

I generally have the radar display at 2 and 6 mile scales when in the open ocean, but gradually decrease that as I enter traffic and scale it down to .5 and 1 mile near a harbor entrance. The screen shot shows my set up and a guard zone at 2 miles which I activate when my wife is on a wheel watch. Excuse the finger prints, its a touch screen.

Coming through the LA Harbor entrance yesterday I had a very close call with a 40 something boat who was on full plane in pea soup fog 100-200 ft Vis. I was doing 5 Knots and he would not answer on 16 as he approached me. He literally made a turn to avoid me as he broke through the fog and saw my vessel. At that point I got on the VHF and asked everyone in the area to reduce their speeds due to the heavy fog, but it didn’t help much -shocker I know. It was a Saturday morning so people were hell bent on getting to the Island and it was opening day for Lobster Season so center consoles were also darting around with their hair on fire.

Regarding AIS, it truly is a great feature to hail another vessel by name. A USCG Cutter was coming out of the LA Harbor in the same heavy fog I am describing when I was entering yesterday and they immediately hailed me by vessel name, switched to another working channel, confirm Port to Port, I told them I could see them on radar and AIS, I offered to turn more to my Starb to give them more room, he said that would be appreciated, and I was back on 16 in less than 20 seconds.

 

[MYTraveler]

Regarding AIS, it truly is a great feature to hail another vessel by name.

Even better, AIS allows you to make a DSC call to the vessel -- very handy if they don't respond to their name. And with DSC, if the radio is on, it will beep annoyingly until the DSC call is answered (or at least for a long time). One off shore the military was hailing a cruise ship by name and it took 10 minutes for the cruise ship to respond. Finally, the military vessel was able to direct the cruise ship to alter its course, unfortunately to a collision course with me. I hailed the cruise ship by DSC, received an almost immediate response and quickly resolved the conflict.

 

[ghost]

A few things to unpack here but I generally prefer radar heading up and I like to manually control my gain, though I suspect the newest radars auto may be superior.

I’ve primarily run two different Furuno open array units for the past two decades, but switched to a used Furuno vx2 dome about two years ago when the old Furuno crossed over. Before this my chart and radar was always separate.

Two weeks ago we had dense smoke combined with fog, really challenging conditions, combined with not broadcasting ais lead to a couple “incidents “.

A.). While cruising along, the fog lightened just a little a small sailboat with a radar reflector cruised by close enough for me to see, but I was not tracking him on radar. That was a bit alarming.

B.) While completely stopped on the edge of a narrow passage drifting very close to shore in the current I experienced dizziness from vertigo, the final trigger was the heads up chart rotation.


For A, the sighting of the sailboat, was just before arriving at Friday Harbor about 7am. All morning there was very little recreational traffic and I had very few blips on my radar for the past few hours and was running on chart/radar overlay at a range of maybe two or three miles. Big enough to get ones bearings, but it was just too far of range to see the sailboat. I played with manual gain low stc, tuning, stretch, and could get just a slightly better return, but the real solution was swapping to side by side chart/radar with two different ranges. Overlay at two different ranges would be preferred, but that is not an option. I’d really like to see this scenario with the newest Furuno NXT that I’ve been itching for. From experience I know the open array CRT, manual tuned unit I had run until it died would have picked up that sailboat at that range. The dome just wouldn’t. For the most part, the auto tune settings did seem to get about 85% of what was out there to see.

For B, the vertigo. My biggest mistake was coming to a relative stop. Without enough movement the gps based course heading caused the chart overlay to keep swapping, telling my brain I was spinning. When I looked into the blank fog it was ten times worse. The problem was that I was in shallow enough water to immediately go aground if I started moving in the wrong direction. So here is an interesting vote against heading mode in this scenario.

 

[DDW]

To clarify, head up on radar is the most stable (it's natural state) and N up on charts is most stable. Any other mode requires additional sensor inputs and calculations, with associated errors (pretty small these days).

I do both overlay and not, and head up and N up. I believe you get more information out of the data not overlayed, but it requires extra processing time in your brain - what pilots call "workload". In open water with sparse traffic the workload is low and you may want the sparse fine grained picture. In tight water and/or with lots of traffic the workload is high and anything that reduces the workload is an advantage, so head up and overlay - look at the screen, look up out the window and they match with no processing. The aircraft getting ahead of the pilot due to workload overwhelming processing is the cause of many accidents. Less so in slow moving boats, but the same concept applies.

 

[mvweebles]

Related question. In open water, what range do most people run? Coastal, outside shipping routes and at displacement speed, I usually run in the 6-mile range offset so there's about 2/3rds of the range in front, 1/3rd behind. Works out to around 10 nms in front, 4 or so behind. I'll occasionally zoom out to see what's out there, but I find resolution starts to fade for smaller sets. Dual display certainly adds options, but curious what others are doing.

Peter

 

[psneeld]

Outside of probable shipping areas, 3 mi is plenty for me as I can evaluate and alter course in plenty of time. Offset with more forward most of the time.

If running a coastline or a line of marks beyond 3 mi, I may increase to keep those targets on the scope for orientation.

Most of the lower powered RADARSs (2&4kw) I ghave used (especially domes), seem to give a better presentation because of multiple reasons at 3nm in my opinion

 

[AlaskaProf]

North up on my Coastal Explorer charts because all the textual detail goes awry in any other mode and heading up on the radar because I don't want to interpolate about threats.

I find no difficulty reconciling the two, but that may have something to do with 30 years of air traffic control where all the displays and charts are north-up, but you are working with ten or fifteen targets on many different "track-ups".

Oh, yeah, auto tuning in good weather, when the crew may be learning, but manual, constant optomising when I am using the radar "for real", and the crew is relegated to coffee making.

Someone above made the argument re: overlays obscuring symbols or targets. I concur.

 

[tozz]

Recent thread on radar in fog got me thinking about how people use modern RADAR. In the CRT days, tweaking the tuning was a regular activity - auto tune on modern sets is much better. But is it good enough?

For people who regularly use their radar, how many use manual tune functions vs auto-tune? How many prefer chart overlay vs separate radar and chart displays? Are the answers situational dependent - perhaps there are weather conditions where auto-tune doesn't achieve satisfactory results?

Peter

I have an older Furuno system. The FR-7111 with the 12" CRT display. I like to keep the radar separated from the chart plotter. I'm using Coastal Explorer with AIS and I don't want to overload that screen with information. I like the separation. I am also in the chart north up, radar heading up camp and I manual tune. I was finding auto tune wasn't cleaning up sea clutter in anything more than light chop and seeing smaller vessels as crisp as when I manual dial it in.

-tozz

 

[tozz]

[snip] Related question. In open water, what range do most people run?

Peter

I run most of the time in more open water at 3 nm and bounce range between 1.5/1/.5 in tighter areas or reduced visibility.

-tozz

 

[AlaskaProf]

3 miles, with an occasional zoom to six or even twelve, for a check of the strategic picture.

 

[O C Diver]

I have a split screen Garmin setup and usually run X and 4X. So if out of the shipping lanes it could be 1 and 4 miles, or in the shipping lanes 2 and 8 miles.

When traveling ICW I usually set 4X as my generally longest line of sight to a maximum of 4 miles. So if line of sight is 1 mile, my settings are 1/4 and 1 mile. Don't
want to give the impression that I'm constantly changing ranges, most of the time it's 1/4 and 1mile. It's on large bodies of water and or ones with more channels for traffic to enter that I bump up the range.

IMO, if you use a dual range display, it's a good idea to consistently keep the ratio the same so that you know when a target on the larger range should appear on the smaller range.

Ted

 

[Wxx3]

I prefer manual tune. Usually run my radar to display 2 ranges. Each range has its own tune, gain, rain and sea clutter. It's pretty easy to make minor adjustments in changing conditions. Sometimes I will tolerate a little more sea clutter to get a solid image on a small boat or buoy. Computer tuning and auto clutter reduction can either be to sensitive or not enough.

I prefer not to use radar chart overlay. Having come from decades of using paper charts, my brain thinks in North Up (never turned a paper chart to figure which way I was going). Having 3 multi function displays plus a computer screen for navigation, it's easy to display what you want and scan between. Prioritizing is also important, most times one is more critical than the other. When chartering, coming out the inlet in the fog, after clearing the inlet buoys, targets are my only concern until I reach the seabuoy. While the radar is running on a separate screen, on a clear day, cruising a narrow channel on the AICW is all about navigation markers. In both cases, I don't need superfluous information.

Ted

A few additions:

I use my radar more than most because I find myself traveling at night more than I should or in bad vsby.

Being a weatherman, I was also familiar with analog weather radar and my analog Raymarine works pretty much the same, but without an azimuth adjustment.

Having said all that, I find a few things of critical importance to using and understanding your radar:

1. When I start the engine and turn on the nav lights, radio, etc, the radar gets turned on. It's critically important that you understand what various returns look like in good visibility, so that if you need to use your radar when you can't see, you know what it's telling you. A separate display is a necessity. In the beginning I thought a combined display would be good, but I quickly understood that too much information on one screen will block critical things at critical moments.

2. Related to that, I always correlate returns I see on the radar with what is on the chart or out the window. Always. That's the only way to make sure your adjustments are correct for the conditions. When I have new crew mates at the helm, that is an exercise I have them do continually.

3. To that end, I never use the "auto" settings. They are invariably wrong and worse, usually with "auto" the sensitivity (gain and filter) is too low, meaning there are less returns, but you don't know what it isn't showing you.

Lastly, I do the above, because there are times, usually at night, when my brain is saying one thing, but my radar and chart plotter are saying something else. I must know to ignore my senses and trust the radar.