Radar brain teaser

[Wxx3]

Please see the attached picture. It is of my Raymarine E80 radar screen.

The question is who can identify what caused thst return if about a dozen blips and tell tails, that start about a mile ahead of the boat and go off at a 45° angle?

A hint. Ihad to adjust the gain a bit to see it.
Yes, I know what it is.

 

[syjos]

Please see the attached picture. It is of my Raymarine E80 radar screen.

The question is who can identify what caused thst return if about a dozen blips and tell tails, that start about a mile ahead of the boat and go off at a 45° angle?

A hint. Ihad to adjust the gain a bit to see it.
Yes, I know what it is.

It looks like a raycon.

 

[SteveK]

It looks like a raycon.

racon=Canadian spelling

 

[SoWhat]

Somebody using a SART beacon to mark their buoy?

US Navy frigate tuning their Main radar?

 

[twistedtree]

It's a plane coming in to land (not taking off, because the streaks are longer further out).

 

[psneeld]

Sart...think Isee 12 pulses

 

[Chrisjs]

Once ran along a similar longer line of blips on an overnight run
Turned out to be lobster pot markers.
Actually saw one with a tall marker pole fly past the PH door at eye level in the dark.

 

[jleonard]

Ufo

 

[O C Diver]

Are they marine creatures of some kind disturbing the water surface? Blue would indicate a softer target wouldn't it?

Ted

 

[High Wire]

A Marine Max boating event.

 

[twistedtree]

So I might be completely wrong, but here’s how I’m reading it.

He’s got echo trails on, and that’s the blue trail behind everything. Yellow is the current return, and blue are past returns since last reset.

The streaks in the target in question have gaps between them. That says the target moved quite a bit between sweeps, so is moving fast, probably a plane

And the streaks further out from land are longer than those closer to land, so those have been present for longer than the streaks closer in, so it’s approaching land, not going away.

I think that’s Wrangell, and probably the Wrangell airport.

 

[ben2go]

Water creatures I think, whales or some such crazy mammal.

 

[psneeld]

To have 12 nearly identical returns of same or graduated size, equal or graduated spacing....usually spell
some sort of transponder return.

I believe morse code would be a RACON....12 pulses I believe is a SART.

Google images show similar returns.

 

[tpbrady]

Since I know where Richard is, I won’t answer, but I am pretty sure there has been one correct answer.

Tom

 

[High Wire]

How many reindeer does Santa's sleigh have?

 

[JohnEasley]

How many reindeer does Santa's sleigh have?

Nine, with Rudolph.

 

[bayview]

I notice a slight curve as with an airplane

 

[psneeld]

Wouldn't the blue shadows indicate a turn of the vessel?

 

[High Wire]

Assuming the radar is spinning 24 RPM, and there are 12 sweeps in 1 mile distance, doing the math: The object covered 1 mile in about 30 seconds.

2 miles per minute or 120 MPH. An aircraft sounds about right. TT's

 

[TG]

SART, see attached doc.

 

[Wxx3]

So I might be completely wrong, but here’s how I’m reading it.

He’s got echo trails on, and that’s the blue trail behind everything. Yellow is the current return, and blue are past returns since last reset.

The streaks in the target in question have gaps between them. That says the target moved quite a bit between sweeps, so is moving fast, probably a plane

And the streaks further out from land are longer than those closer to land, so those have been present for longer than the streaks closer in, so it’s approaching land, not going away.

I think that’s Wrangell, and probably the Wrangell airport.

Good job to one and all.
We were on the way back from retrieval of our shrimp pots and anchor. (That blog post to be published today).

On the way to retrieval, I was tinkering with the radar's gain and sea state to see if I could get it sensitive enough to mark a small pot float, but nothing else.

In doing so, I noticed first a number of my transitory targets were flying birds.

So on our return that afternoon/evening when I saw the landing lights of the 737 on final to WRG, I played with the radar to get that returns.

And yes, each blip was one sweep of the radar.

Merry Christmas to all.

Richard on Dauntless in Wrangell Alaska



The plane after landing and having turned around to go to the terminal.

 

[Capt Mike]

I learned something today. Thanks

 

[JohnEasley]

Thanks for the lesson, Richard. Now I have something to play with next weekend on the boat.

 

[AlaskaProf]

Nine, with Rudolph.

Ten. Don't forget Olive the other reindeer.

 

[SteveK]

Wxx3
I waited to ask this question until thread was resolved.
You were 1-2 NM from the series of blips. My question is I thought marine radar was focused on the horizon, how low was that plane flying, OR is your radar pointing skyward, thus the reason the float was not picked up?

 

[boatpoker]

https://www.panbo.com/sart-whats-that-on-my-radar/

 

[fgarriso]

Ufo

 

[Boat]

RUN, it's the Mccain. Head for shallow water!

 

[twistedtree]

To have 12 nearly identical returns of same or graduated size, equal or graduated spacing....usually spell
some sort of transponder return.

I believe morse code would be a RACON....12 pulses I believe is a SART.

Google images show similar returns.

But wouldn't a RACON echo back towards you?

 

[psneeld]

https://www.navcen.uscg.gov/?pageName=enavRadarBeacons

The displayed response has a length on the radar display corresponding to a few nautical miles, encoded as a Morse character beginning with a dash for identification.� The inherent delay in the racon causes the displayed response to appear behind the echo from the structure on which the racon is mounted.�