Active radar reflector response to broadband radar

[Cyrus Safdari]

I am not sure if I understand this but apparently some of the new generation of broadband radars radiate insufficient power to trigger the active radar response until the ships are pretty close.

So according to this chart by EchoMax, the newer Raymarine Quantum 2 raders will trigger an EchoMax active radar enhancer response only at 1.5 nm? That's closer than eyesight & far too late to avoid collision

https://www.echomax.co.uk/active-faq

I am not sure what portion of the market of new radar reflectors these all represent and how big of a problem this is, seems folks should reaalllly not rely on active radar reflectors as much as they do. Back to the good ol' passive reflector up the mast...

[goboatingnow]

Originally Posted by Cyrus Safdari

I am not sure if I understand this but apparently some of the new generation of broadband radars radiate insufficient power to trigger the active radar response until the ships are pretty close.

So according to this chart by EchoMax, the newer Raymarine Quantum 2 raders will trigger an EchoMax active radar enhancer response only at 1.5 nm? That's closer than eyesight & far too late to avoid collision

https://www.echomax.co.uk/active-faq

I am not sure what portion of the market of new radar reflectors these all represent and how big of a problem this is, seems folks should reaalllly not rely on active radar reflectors as much as they do. Back to the good ol' passive reflector up the mast...

Sorry 1.5 is plenty distance to avoid another yacht. Ships don’t use echo maxes. Passive reflectors on FMCW radars are even worse anyway.

I’m not sure what your point is. Broadband radars are so good , the yacht with them will see you echomax or no echomax.

Very few people have active radar target enhancers anyway

[Jim Cate]

At such short ranges the natural response signal from the vessel with the active reflector should be very easily and reliably seen by the interrogating radar. No reflector of any sort is needed.

Jim

[Cyrus Safdari]

Originally Posted by Jim Cate

At such short ranges the natural response signal from the vessel with the active reflector should be very easily and reliably seen by the interrogating radar. No reflector of any sort is needed.

Jim

The point is to be seen well, way before such short ranges, thus improving chances of avoiding collision

[goboatingnow]

Originally Posted by Cyrus Safdari

The point is to be seen well, way before such short ranges, thus improving chances of avoiding collision

Sure bit broadband radar is generally very good and fitted to a lot of yachts. They’ve sent you already

[Cyrus Safdari]

Originally Posted by goboatingnow

Sorry 1.5 is plenty distance to avoid another yacht.

Doubtful depending on the circumstances and speed of vessels but what's the point of a radar enhancers that only enhancers at 1.5 NM? I can see that far without any enhancement or even radar
For comparison I set my AIS at 2.5 NM, some set the AIS even farther

Ships don’t use echo maxes

The question isn't whether ships use echomax, the question is whether my echomax will respond to their low power radar signal in time

. Passive reflectors on FMCW radars are even worse anyway.

Of course passive radar reflector swill be worse than active ones naturally, they also cost a fraction. That's why cruiseres switch to active refectors
Again not really the issue

I’m not sure what your point is.

That's apparent lol

Broadband radars are so good , the yacht with them will see you echomax or no echomax.

So you're suggesting broadband radar makes active enhancers obsolete?

Very few people have active radar target enhancers anyway

Very few people go yachting

Active radar enhancers are stnd recommended kit for offshore cruisers. The GGR requires them. If the new broadband radar signal cannot be picked up in time , that is an issue

[NPCampbell]

If a solid state radar can transmit and detect the reflected signal from a 2' object 2 miles away then an active reflector should definitely be able to pick up the un-reflected signal from 2 miles away unless its detection circuitry is poor.

[Cyrus Safdari]

Originally Posted by NPCampbell

an active reflector should definitely be able to pick up the un-reflected signal from 2 miles away unless its detection circuitry is poor.

As I understand it the new broadband radars use such low intensity waves that the active enhancers don't initially recognize it and so dont respond until the signal source is too close

According to EchoMax's own webpage this is in the 1.5 to 2.5 nm range which is effectively useless as like I said I set ny AIS to 2.5nm

Im sure the new radars on the ships are so wonderful and sensitive but Im not sure if that's enough to say active reflectors are therefor unexessary as by then the ship must have seen you

Lets remember why we use active radar enhancers it is not just a question of better visi ility to a passing tanker, it is rather because ships are inattentive to what they do see & so more likely to respond to an actively returned blip as opposed to a passive reflection, or so the theory goes. It is supposed to make you a more certain blip to avoid running over if they can. That inattentivess is what makes a passive radar reflector not as useful as active reflectors, not just the fact that an active radar reflection can be picked up better

The ship will indeed probably have the ability see your boat regardless of whether you have active or passive reflectors, just because their array is stronger & higher. But just because they have the ability doesnt necessarily mean theyre paying attention to start with. The actuve return blip is supposed to address that (but not if it only kicks in at 1.5nm)

[StuM]

Originally Posted by Cyrus Safdari

The ship will indeed probably have the ability see your boat regardless of whether you have active or passive reflectors, just because their array is stronger & higher. But just because they have the ability doesnt necessarily mean theyre paying attention to start with. The actuve return blip is supposed to address that (but not if it only kicks in at 1.5nm)

You've just said that ships have stronger and higher arrays so the 1.5nm limit against low power broadband is irrelevant.

Also note that the quoted 1.5NM in your link is the minimum for a couple of very low powered transmitters. The majority of those listed trigger at 2-3NM.

How many ships just have such low power broadband radars and how many have radars that will trigger that blip at much longer ranges.

[Anders]

All the big ships has old fashioned radar that should trigger your sea me far away.
1.5 nm is not a lot but should be enough when another yacht is triggering it. By then you should be able to see it on your radar anyway.

[goboatingnow]

Originally Posted by Anders

All the big ships has old fashioned radar that should trigger your sea me far away.
1.5 nm is not a lot but should be enough when another yacht is triggering it. By then you should be able to see it on your radar anyway.

Exactly this is why i think the OP is confused. Only yachts carry active reflectors. There primary goal is to alert the carrying yacht , a secondary goal is to return an enhanced echo.

Modern radars often do not display such enhanced pulses anyway , ie it’s of little benefit to a receiving yacht. ( see the echpmax FAQ for more detail )

Small boat radar especially FMCW , is much better then heretofore , so the value of an enhanced return is now of dubious benefit.

This has no relevance to ships. They use full power X and S band radar so these rather outdated active reflectors remain as useful as before.

Hence I don’t see any cause for concern , modern yachts with broadband radar will see you active reflectors or not.

[NPCampbell]

Originally Posted by Cyrus Safdari

As I understand it the new broadband radars use such low intensity waves that the active enhancers don't initially recognize it and so dont respond until the signal source is too close

The average power of a solid state CHIRP style radar is close to that of a magnetron based radar of approximately the same capability. When you see a magnetron radar listed as 2kw, that is peak pulse power over a very narrow sub-second pulse, not the average power. Obviously the radar doesn't consume 2kw. Solid state radars use maybe 30% less average power but they transmit a much wider pulse and repeat it far more often than a magnetron radar.

This is why I believe the capabilities of this active radar reflector are obsolete. CHIRP is here to stay because it provides advantages over magnetron based radars (pulse amplification,heterodyne,blind range,doppler, instant on etc). If the circuitry in the transmitting radar can pickup a considerably weaker reflected radar signal than the active reflector then what good is the reflector? You are better off running a lightweight passive reflector on the end of a pole.

Originally Posted by Cyrus Safdari

According to EchoMax's own webpage this is in the 1.5 to 2.5 nm range which is effectively useless as like I said I set ny AIS to 2.5nm

Im sure the new radars on the ships are so wonderful and sensitive but Im not sure if that's enough to say active reflectors are therefor unexessary as by then the ship must have seen you

Are you advocating that the dog's tail should wag his body? Don't sacrifice the benefits of modern radar to meet the criteria of one brand of active radar reflectors.

Originally Posted by Cyrus Safdari

Lets remember why we use active radar enhancers it is not just a question of better visi ility to a passing tanker, it is rather because ships are inattentive to what they do see & so more likely to respond to an actively returned blip as opposed to a passive reflection, or so the theory goes. It is supposed to make you a more certain blip to avoid running over if they can. That inattentivess is what makes a passive radar reflector not as useful as active reflectors, not just the fact that an active radar reflection can be picked up better

The ship will indeed probably have the ability see your boat regardless of whether you have active or passive reflectors, just because their array is stronger & higher. But just because they have the ability doesnt necessarily mean theyre paying attention to start with. The actuve return blip is supposed to address that (but not if it only kicks in at 1.5nm)

Radar is not aware of an "active blip" or a "passive blip". It is only aware of the strength, delay and frequency of the return signal. If the strength is beyond the clutter levels of the radar it gets displayed.

[Cyrus Safdari]

Originally Posted by NPCampbell

This is why I believe the capabilities of this active radar reflector are obsolete.

ok one more vote for obsolete

Are you advocating that the dog's tail should wag his body? Don't sacrifice the benefits of modern radar to meet the criteria of one brand of active radar reflectors.

My radar and my active radar reflector are two separate matters of course, there is no sacrifice going on there though I dont have a Chirp radar

The issue is how much active reflectors are nowadays reliable or not

Radar is not aware of an "active blip" or a "passive blip". It is only aware of the strength, delay and frequency of the return signal. If the strength is beyond the clutter levels of the radar it gets displayed.

As I understand it of course once the radar identifies a target then it makes no real distinctions however the selling point of active reflectors is

1- it presents a much better signal than the current passive reflectors
thus making you more likely to be seen
Is this still the case?

2- *Apart from what the ships radar picks up* (or not) the active blip was supposedly more likely to *get the attention of the ships operators* by making you "look like a tanker" due to the much better signal.

Is this still the case?

Reality is an entirely different matter, I've witnessed plenty of tankers operating with radar turned off or completely disregarding their radar

Guess Im just debating where and whether to moubt my Echomax

[Cyrus Safdari]

Originally Posted by goboatingnow

Exactly this is why i think the OP is confused. Only yachts carry active reflectors. There primary goal is to alert the carrying yacht , a secondary goal is to return an enhanced echo.

Modern radars often do not display such enhanced pulses anyway , ie it’s of little benefit to a receiving yacht. ( see the echpmax FAQ for more detail )

Small boat radar especially FMCW , is much better then heretofore , so the value of an enhanced return is now of dubious benefit.

This has no relevance to ships. They use full power X and S band radar so these rather outdated active reflectors remain as useful as before.

Hence I don’t see any cause for concern , modern yachts with broadband radar will see you active reflectors or not.

Well I was using the term ship as a general term, meaning whatever other floaty thing out there that can possibly collide with me
Whether yachts or ships big or small. If their radar does not cause an enhanced return signal then indeed the active reflectors may be obsolete as you say.

[Cyrus Safdari]

Originally Posted by Anders

All the big ships has old fashioned radar that should trigger your sea me far away.

OK good to know thank you
Now I just have to worry about smaller vessels
But what about in 5 yrs? Is the radar tech on big ships going the same way?

1.5 nm is not a lot but should be enough when another yacht is triggering it. By then you should be able to see it on your radar anyway.

Yes but at 1.5nm do I even need an active relfector? I mean, by then I should show up as a very clear PASSIVE signal anyway well before then so really If my reflector is going to only kick in at 1.5nm this is not very useful.

The question is not MY reaction at 1.5nm and whether I can avoid collision at that distance, the question is the reaction of the OTHER boat that has picked up my enhanced signal but only at 1.5nm. I hopefully will have managed to see the oncoming boat with AIS or even eyesight at before 1.5nm; I'm worried about what the other guy is seeing and doing.The enhaced signal is supposed to alert them not me



Hell if I ever came within 1.5 nm of a bigger boat on collision course I'd need a change of shorts