The AN/ASG-21 fire control system's dual search track radar of the M61A1 Vulcan 20mm tail cannon of early B-52H models, searching targets using the raster scan method

[-]

ThaddeusJP@reddit

Fun fact: the B52 has an air to air kill

https://www.sandboxx.us/news/how-b-52-bombers-shot-down-enemy-fighter-jets-in-vietnam/

[-]

LARPerator@reddit

Does this mean the B-52 has more A2A kills than the F-22?

[-]

MineOutrageous5098@reddit

That's exactly what came to my mind when I read that. Poor f22, no one dares pick a fight with it.

[-]

It suffers from success. They also won't send it in unless everything's going wrong because losing an F-15 is bad, losing an F-22 is terrible. They don't want to risk letting it handle standard patrols.

[-]

Pynchon_A_Loaff@reddit

The F-22’s problem is that the F-15 and F-16 hunted its prey to extinction.

[-]

dan_dares@reddit

If the F22 could read, it would be very angry.

Franklin will tell him

[-]

Forte69@reddit

Another fun fact: A HARM locked onto one of these radars and hit the tail of a B-52. It survived with heavy damage and was named “In HARM’s way”

https://www.twz.com/10314/the-time-a-f-4g-wild-weasels-anti-radiation-missile-blew-apart-a-b-52s-tail

[-]

Pynchon_A_Loaff@reddit

And this resulted in all of this hardware being removed from the B-52H.

I wonder if the USAF ever considered mounting a DIRCM in place of the tail gun.

[-]

Wahgineer@reddit

Fun fact (taken from the same article): the B52 can be deployed as a CAS aircraft in uncontested airspace.

[-]

greentanker1@reddit

Tbf, basically any aircraft with weapons can be deployed as CAS if there's nothing to shoot it down, doesn't take away from how crazy that statement is though

[-]

hifumiyo1@reddit

Like Afghanistan

[-]

glenn765@reddit

Without looking, and based on the PFE a long time ago, I'm saying the gunner's name is Turner. Time to check...

[-]

QuarterlyTurtle@reddit

What’s the point of having two radars? Just to search faster? So it can still search while one is tracking a target?

[-]

Pynchon_A_Loaff@reddit

Yes. Some SAM systems are like this. You can continue to track other threats while locked on to your target.

[-]

Enough-Goose7594@reddit

I would imagine for continuous coverage.

[-]

glytxh@reddit

Their out of phase movement is what’s intriguing me the most. If they’re synchronised, it’s not in a basic linear fashion.

[-]

Ace861110@reddit

They look to be mirrored vertically and horizontally. I will bet you that it’s for coverage overlap.

[-]

I_am_BrokenCog@reddit

you lost your bet. read above for the winning bet.

[-]

Ace861110@reddit

It’s actually below (in the collapsed comments for some reason) for any that are curious.

[-]

I_am_BrokenCog@reddit

my bad! at least you found it :).

[-]

wrongwayup@reddit

I would have thought you'd specifically want them to be unsynchronized.

[-]

Enough-Goose7594@reddit

Yea, they do seem a bit bonkers. There is surely a purpose and pattern beneath the movements.

Someone smarter than me... interject!

[-]

SanargHD@reddit

It seems to me as though both are doing the same pattern but the upper one is just moving slightly faster.

[-]

Business_Support3382@reddit

Cells..
Interlinked..
Cells..

[-]

Billy_McMedic@reddit

With these older radars, you could only really either scan or lock, as the antenna and electronics of the time weren’t sophisticated enough to be able to do track while scan.

This could lead to an issue for the rear gunner, as when they locked a target, they became blind to other potential targets that might have posed an additional threat that needed addressing. Having the second dome meant that, while one radar locked, the other could keep scanning so the gunner could see if another radar track was a higher priority than the one they currently had locked

[-]

pick_your_user_name@reddit

On the movement specifically though, it’s called a raster scan. Basically the radar is scanning a rectangular area in a systematic fashion, from right to left, then it takes a small vertical step and goes right to left again. This gives it the range, azimuth and elevation of a target in the zone it tracks. Modern radars do the exact same thing btw, but with an AESA for example instead of mechanically moving parts it’s thousands of tiny transmitter receiver modules steering the beams.

[-]

Enough-Goose7594@reddit

"really expensive math"

[-]

thrashmetaloctopus@reddit

Yeah until much more recently if you wanted TWS capability you needed 2 separate radars

[-]

glytxh@reddit

Seems pretty obvious now it’s explained to me haha. Thanks!

Really cool to see in action like this. Almost looks modern if you ignore the lack of array.

[-]

Raguleader@reddit

I'm guessing that one antenna is transmitting, and the other, following just behind, is receiving. Or maybe the out of phase movement is to help spot fast moving threats by playing "spot the difference" between the two scans with two different transceivers.

[-]

Shankar_0@reddit

We're talking about light here.

186,000mi/sec

[-]

jestertoo@reddit

Nope.. light travels wayyyy faster than that out of sync you see.

Two radars so that one can continuously track a target and steer the gun while the other continues to scan.

[-]

Raguleader@reddit

That makes more sense.

[-]

glytxh@reddit

It looks like really really expensive maths.

My favourite kind of engineering.

[-]

LeptonWrangler@reddit

If you watch carefully youll notice they are at different frequencies.

They move in and out of phase

[-]

I_am_BrokenCog@reddit

you are watching closely, but projecting what you think you see and calling it reality.

The movement isn't related. wiki read Track While Scan limitations of single-radar systems.

[-]

theusualsteve@reddit

Semi related but, radio telescope arrays (the ones with ~30 big dish antennas on a hillside) actually look like they are randomly scattered because they are placed "randomly" in a gaussian distribution. This actually gives the array more resolution than if they were placed in a perfect grid. (There are exceptions ofc)

I wonder if theres any correlation to a random-ish scan pattern in these arrays not being coupled.

[-]

glytxh@reddit

The maths behind interferometry with arrays like this is straight up witchcraft.

[-]

RentAscout@reddit

Early method of track while scan. They are independent in operation.

[-]

xrelaht@reddit

If it sees an incoming enemy, one of them is used to control the gun while the other keeps scanning for other incoming targets.

[-]

maurymarkowitz@reddit

Track while scan. I believe the lower one continued scanning while the upper one would lock on.

Recall at the time that the way you "locked on" was to keep the dish pointed at the target, so when you did so normally you would lose tracking capability. Dual-dish systems like this solved this problem, if you had the room for it.

[-]

SalTez@reddit

Yes, one was dedicated for continous search and the other for tracking to provide data for a firing solution

[-]

graybrainpaste@reddit

My first job in the AF was maintaining this system - gunner could take control of an antenna and steer in azimuth while antenna nodded up and down (elevation)

[-]