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
Posted by Xeelee1123@reddit | WeirdWings | View on Reddit | 73 comments
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.
LARPerator@reddit
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)
I_am_BrokenCog@reddit
What was the life cycle of these units like? Were they durable?
CocoSavege@reddit
Huh! Why is azimuth manual but pitch radar based?
If I may add, how is lead calculated?
BlitzShooter@reddit
Different frequency bands
Shankar_0@reddit
One module can only scan so fast. There comes a point where if you need to increase the scan rate, you have to work in parallel.
It would also be helpful for target confirmation, noise elimination and error reduction.
iwantogofishing@reddit
"are you still there?"
notam161126@reddit
Mig? Mig? Hello where’s the freaking MIG.
IndependenceStock417@reddit
Oh fuck he's not there! Oh no! Cmon c'mon! Did you see where he went?
dan_dares@reddit
He's where he isn't
Bipogram@reddit
Unlike the missile.
Cheese_Grater101@reddit
HELLO MIG, MIG WHERE THE HELL ARE YOU, MIG, I WANT TO TALK ABOUT EXTENDING YOUR JET WARRANTY
commissarcainrecaff@reddit
Me, looking for that tiny bit of Warhammer model I dropped on the carpet
(It's gone)
MELONPANNNNN@reddit
Man I pity the maintainer who had to look after those bearings
haikusbot@reddit
Man I pity the
Maintainer who had to look
After those bearings
- MELONPANNNNN
^(I detect haikus. And sometimes, successfully.) ^Learn more about me.
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AlbinoAkon@reddit
What is this doco??
swishflip96@reddit
Needs googly eyes balls
1OptimisticPrime@reddit
These radar act suspiciously, as if the Japanese Jiggle Physics was actually training the model.
Ultimately, these are just swinging titties with tassle pasties😅🤣
rakithaya@reddit
looks like two of these
hifumiyo1@reddit
And that just helps radar detectors find your output. Which is why they canned the tail guns eventually
joshuatx@reddit
They took these out after the Gulf War when a B-52 and F-4G engaged each other. No casualties but a HARM missile did hit the B-52.
https://theaviationgeekclub.com/friendly-fire-incident-caused-deactivation-buff-tail-gun/
myrsnipe@reddit
In harm's way
myrsnipe@reddit
In harm's way
cor1912@reddit
My cat does this when he sees a bird he can’t reach. Always wondered what he was doing
PanzerGun@reddit
When i meet the radar of absolute disagreement
billysugger000@reddit
That's strangely off-putting.
MegaPegasusReindeer@reddit
Like chameleon eyes
epsilon4_@reddit
RIP servo
Misraji@reddit
I can hear then going “Where? Where? Where? Where? …”
Warrington17415@reddit
Reminds me of the two bickering tailor robots in Woody Allen's "Sleeper".
404-skill_not_found@reddit
I had no idea
Xeelee1123@reddit (OP)
Source: https://youtu.be/d-Tn5JwMEtA
Source: https://en.wikipedia.org/wiki/M61_Vulcan
Source: https://www.radartutorial.eu/19.kartei//11.ancient9/karte052.de.html