wuzak
Captain
I wouldn't be surprised if 80-85% was the percentage of bombs dropped on the country that was the target of the raid.
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Ok, the ww2 USAAF bombing run was pretty accurate. Some bombardiers could be really accurate and hit the target with 80-85% of precision.Then the bomb sight, was vary good. I think was the best one in the 1940s.But at an alt. of 25.000ft it's very difficult to spot the target so , the man was everything, not the machine .Then , the istruments could help him to bomb it .
Probably hard to measure anyway, and being a very small factor in the overall errors measured operationally.
Post war the RAF used developments of the Mk XIV/T-1 sight in its V-bombers. The SABS seems to have been a dead end, and as far as I know nobody has written a reference for it, nor do any exist in the public domain.
Cheers
Steve
I got a couple of questions regarding aerial-bombing, particularly level-bombing with iron-bombs...
I. Measuring Average Error
There's CEP which if i recall is the radius where half the bombs land. There's something like average/median radial error which I think is the radius in which 100% of the bombs fall. I'm curious if there's any way to convert between the two?
I'm also curious about if the average error is measured on where each bomb lands relative to where it should be, where each aircraft's bomb-track/bomb-train lands versus where it was intended to, or where the whole bomber formation/stream lands it's bombs versus where it should.
II. Bomb-Train/Track
This has to do with the fact that the bombs do not appear to all be released at the same time but over the course of a couple of seconds. Since each bomb follows a ballistic path after being released, would I be correct to assume that if one bomb is released a second ahead of the next they would land however many feet per second the bomber flies?
I would have never thought they'd have developed the Mk.XIV over a gyro-stabilized system, but looking at Koopernic's data regarding the Vulcan's bomb/nav system using data fed from the doppler-updated INS into the Mk.XIV, those accuracy figures look fantastic.Post war the RAF used developments of the Mk XIV/T-1 sight in its V-bombers. The SABS seems to have been a dead end, and as far as I know nobody has written a reference for it, nor do any exist in the public domain.
Makes sense to meWikipedia says that coastal command mosquitos which used the Mk.XIV with a radar Altimeter didn't have the 10'second run up restriction which to me suggests that the 10 second run up was only to let the altimeter or variometer stabilise.
What period of time was the Doppler and Green-Satin system used?Post war V force bombers received a Doppler navigation radar to update the INS "green satin" that could measure true ground speed and drift and this could be fed into the Mk.14 directly rather than being manually set.
Wait... it successfully landed a bomb 300 feet ahead of and 120 feet to the side of the aim point?When Britain dropped its first a-bomb in Maralinga from a Vulcan it was from 30,000ft using the MK.XIV after a radar run up. The bomb was of target 40 yards in azimuth and 100 yards down range.
63 + 27 = 90I'm not sure if I'm missing anything here, but if I do my math 63+27 = 100%: Am I correct to assume it's 27% instead of 26%.
I'm sorry, I meant 37%. I'm not sure why I made such a silly miscalculation
I dont know it is not my subject and it wasnt my post, I just pointed out that 26 + 64 doesnt equal 100 On almost every issue you seem to want the most simplistic answer to complex questions. To understand CEP read about it but to understand it you need a basic knowledge of statistics.Uh, I don't know how to do either the Standard Deviation or the Gaussian function. Algebra is the highest I've gone in math -- you'll have to bear with me.
Regardless am I supposed to use 1.26 x average radial error to get CEP?
When Britain dropped its first a-bomb in Maralinga from a Vulcan it was from 30,000ft using the MK.XIV after a radar run up. The bomb was of target 40 yards in azimuth and 100 yards down range. Besides bomb fall times of 50 seconds and targets that were 10km ahead of the bomber couldn't realistically be tracked.
If this is Operation Buffalo, then a low yield (3 kiloton) version of the 40 kiloton 'Blue Danube' weapon was dropped from 35,000 ft and from a Valiant on 11th October 1956. The aircraft was WZ366 of 1321 Flight, 49 Squadron, piloted by Squadron Leader T Flavell. Both he and the bomb aimer, Flight Lieutenant E Stacey, were awarded the Air Force Cross for their part in the operation.
There has been much criticism of this series of tests, but the original plan, to drop a 40 kiloton weapon to explode at 1,200 ft was abandoned because of worries that the fuzing system might fail causing an explosion at ground level. The 3 kiloton weapon, which functioned perfectly, exploding at 500 ft as planned, was a safety compromise.
Operation Antler, a series of tests designed to perfect the Blue Danube and Red Beard warheads were planned for Maralinga in September/October 1957, but were cancelled when plans were made for the the second phase of the British nuclear programme, the dropping of the first thermo-nuclear megaton weapons in what would be known as Operation Grapple. Maralinga was not a suitable venue, Christmas (Kiritimati) Island and Malden Island were the selected venues instead.
Incidentally the first series of Grapple tests, between 15th May and 19th June 1957, three weapons were dropped dropped from 45,000ft, again by three different Valiants (XD818, XD822 and XD833) of 49 Squadron, exploding at 8,000ft above Malden Island to prevent the fireball touching the ground and causing "excessive radiation problems." Further weapons were dropped in subsequent tests over Christmas Island before the final two were detonated, suspended from tethered balloons. In September 1958 Britain's 'H-Bomb' was available to the V bomber force.
The Valiant was the only British bomber to drop a live nuclear weapon, neither the Victor nor the Vulcan ever did. The ban on atmospheric testing probably ensured this.
Cheers
Steve
Zipper you seem to misunderstand what statistics are about. People collect information and compile them to make sense and draw conclusions. The normal or gaussian curve is frequently used because many sets of data form a Gaussian curve or spread. In specific fields with specific data the gaussian curve may be useless or inaccurate. In tems of new born babies (as an example) babies height and weight will have a spread which is Gaussian or normal but the spread of boys and girls isnt because 99% are either boys or girls and about 51% of babies are boys. CEP was developed because munitions are specific, bombs and missiles spread around an aiming point are similar to a Gaussian spread in some cases and different in others. CEP was developed to provide useful information on targetting, it may be possible to convert to another measure or it may not. Some Laser guided missiles hit the target or they self destruct and so they have no spread on impact. CEP is also not a measure of accuracy it is a measure of "grouping" around a mean point, the difference between this point and the aim point is the "bias" which is also a useful measure as it shows up errors in the aiming system.Uh, I don't know how to do either the Standard Deviation or the Gaussian function. Algebra is the highest I've gone in math -- you'll have to bear with me.
Regardless am I supposed to use 1.26 x CEP = Average Radial Error?
I understand that, so there's no confusion here...Zipper you seem to misunderstand what statistics are about. People collect information and compile them to make sense and draw conclusions.
So, in some cases they aren't even compatible? Certain laser-guided ordinance being an example?The normal or gaussian curve is frequently used because many sets of data form a Gaussian curve or spread. . . CEP was developed because munitions are specific, bombs and missiles spread around an aiming point are similar to a Gaussian spread in some cases and different in others. CEP was developed to provide useful information on targetting, it may be possible to convert to another measure or it may not.
I thought accuracy was basically how close you hit to where you actually intended to hit?CEP is also not a measure of accuracy it is a measure of "grouping" around a mean point, the difference between this point and the aim point is the "bias" which is also a useful measure as it shows up errors in the aiming system.
I'm surprised nobody connected the dots. I'd have figured if the bombs came out in 3-6 seconds, I'd have started bomb-release 1.5 to 3 seconds before the target was reached. That way if some bombs landed long, the earlier releases would have struck their target, if I landed short, the late releases would smack the target. Also when it came to releases, it seemed the first few bombs started to come out, then the bulk came out in the middle, then a few more came out at the end (at least looking at the B-52, it looked like that).Another point just occurred to me. Watching old video on "The World at War" some USA bombers released all bombs together, while others were on some sort of spaced release about half a second between each bomb. In the latter case only the first bomb was actually released onto the target.
There were photo-reconnaissance P-38's and stuff along with B-17's and B-24's with photo-flash bombs and the H2X scopes to analyze impacts (how does that work, when the radar return starts changing from a building being altered in shape)?To add to the excellent points above, the Americans used group pattern analysis precisely because they couldn't distinguish individual bomb strikes, but could more often (but by no means always) discern group patterns. The US analysts used 'vertical' photographs taken by PR aircraft accompanying the missions, 'vertical' photographs taken by some of the bombers and, for blind bombing, 'scope' photographs taken of the H2X display (one every sixteen seconds on the bomb run up to bomb release, others less frequently).
And since we had been planning to use formation bombing for self-defense, it was the most simple way of analyzing all the data in one fell swoop...The Americans analysed each group's bomb fall, from all its aircraft, as if it was the result of a single aiming operation.
And they collated all the photographs, and then used them to roughly estimate each aircraft's accuracy, each squadron, and so on...The British, by night, didn't even attempt to to see individual bomb strikes, they were estimated by a rather complicated extrapolation from the bombing photograph which all the bombers took.
So all the bombs sort of mixed in with the bomb-trains of all the other aircraft in the formation?There was discussion about the US intervalometer (British automatic bomb distributor) earlier. The settings obviously altered the size of each bomber's pattern, or more correctly the distribution of its salvo. An American analysis from 1943 explains.
"A ship's load will be dropped in a train, by intervalometer or manually, producing a "stick" of bursts along the track. From typical altitudes (20,000-25,000 feet) the sticks from each plane depart widely from the theoretical rectilinear equispaced configuration, and sticks from different ships are usually mingled in quite haphazard fashion. The resulting aggregate of bomb bursts on the ground take the form of a very irregular cluster or "blob", in which practically no system or order is discernible.
And, to recap, the formations used in 1943 were around 2340 feet wide, and narrowed to 500 yards or 1500 feet by 1944?The size of a bomb pattern varied widely according to many factors, intervalometer settings, altitude, type of ordnance etc., but the average US pattern in 1943 covered an area 3,700 feet (1128 m) long and 2,500 feet (762 m)wide.