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Radar Bomb Scoring
- the Air Force utilizing Nike equipment & operators
The purpose of this section is to present information about Nike (Hercules) as part of the Air Force "Radar Bomb Scoring" efforts.
A quick background:
I got out of the Nike program before "Radar Bomb Scoring" for the Air Force
so all of the following is contributed by BOB RENFRO K4OF - k4of @ hotmail . com - Mount Pleasant, NC 28124 - blog :-))
Material in italics is commentary by Ed Thelen.
Table of Contents
- Historically, Bombing from aircraft over 10,000 is marginally accurate
- Mission of Radar Bomb Scoring
- Method, with Nike Hercules
- Method, with railroad train
- "Sacremento" - ? a fixed/permanent installation ?
Historically, Bombing from aircraft over 10,000 is marginally accurate
This article seems to cover the years 1960 to about 1980, and seems to be primarily radar used in the aircraft to "see" the ground and hopefully the target, or some offset from the target.
Aircraft bombing developments since about 1980 with enhanced accuracy using bombs guided by various means such as laser pointing, GPS, etc. are not included.
With the coming of radar in WWII, flying over enemy guns at less than 10,000 feet was excessively dangerous. The coming of the proximity fuse raised this altitude.
It was evident that the claim of "Nordon Bombsight 'Pickle Barrel' bombing brag of the 1943 era was bogus.
British Night Bombing hoped to hit the right city, maybe even with in a mile of the aiming point -
The American Daylight Bombing, if the weather was clear, hopefully was more accurate. But movies and still pictures of bombs hitting all over the place were not impressive. To "knock out" the ball bearing factories at Schweinfurth took multiple raids with high losses each raid. http://en.wikipedia.org/wiki/Second_Raid_on_Schweinfurt
Probably nuclear weapons (unless trying to knock out underground installations) seemingly did not need much aiming (if you could see the target).
But the Air Force seemingly also wanted to hit targets, with conventional bombs, using radar guidance to overcome night, clouds, smoke, and other obscuring problems.
So lets have the bomber crew practice hiting an unseen target in a complex city environment. There are at least two choices:
- Build a fake cities hoping to replicate the radar image, and be able to drop inert bombs - safely -
- Use real cities, but don't drop anything (getting hit by an inert missile from the sky is likely to ruin your whole day !!
Mission of Radar Bomb Scoring
- permit bomb crew practice/evaluation and technique evaluation by
- determining aircraft position and velocities at time of pseudo bomb release
- and estimating where the bomb would be when it exploded
- without risking people and objects on the ground
Fri, Apr 10, 2015 7:03 pm
Radar Bomb Scoring Division
The Radar Bomb Scoring Division was a Strategic Air Command military organization which controlled the RBS units and operations of the 1st Combat Evaluation Group. The division included a maintenance office and as with the preceding 1st Radar Bomb Scoring Group at Carswell AFB, the division had 3 Radar Bomb Scoring Squadrons with RBS detachments at fixed radar stations and at semi-mobile radar stations. The semi-mobile stations called "MDLs (Mobile Duty Locations) were sites set up for SAC special missions [and the] equipment, trailers, books, etc" were stored at Barksdale AFB when not in use. Each squadron manned an RBS Express train, but the squadrons were inactivated in 1966 after Vietnam War deployments had begun. RBS trains were inactivated later in the war after the 1968-9 Project 693 downsized by discharging 1st term SAC airmen up to 11 mos. early. Post-war the annual Combat Skyspot trophy was awarded for the outstanding RBS detachment (e.g., to Ashland Det 7 in 1985).
Fri, Apr 10, 2015 6:29 pm
The cameras would record the jamming effectiveness on the radar display. Ground jammers would jam the aircraft navigation and defense systems. Aircraft would jam the tracking radar and simulate incoming threats to the ground crew.
Nothing aimed at the RBS Express. Radar Bomb Scoring mounted on a train - see here
Air crews used either direct or offset aiming. Targets were corners of buildings surveyed and data on each target entered into the OA-215 computer.
Nike crews played pool and went to work when I arrived. My mission was not the scoring, rather teaching the crews how to do it. I had TDY pay plus $25 per per diem.
Fri, Apr 10, 2015 7:03 pm
from http://a3skywarrior.com/whaletales/bombscoring.htm - more text and pictures in this web site -
In early 1960 I was transferred from TD"B" school at the Naval Air Technical Training Center, Memphis, Tennessee to the Naval Air Facility at Naples Italy. There, I was assigned to work at the Radar Bomb Scoring Unit (RBS Unit) in support of the 6th Fleet Heavy Attack Squadrons (we also supported USAF and RAF aircraft). The A3Ds assigned to the VAHs aboard the 6th fleet carriers would simulate dropping atomic weapons on various targets around the Naples area. We at "Naples Bomb Plot" would track them on our radar, and plot their bomb drops. We would then let the bomber crews know the "Circular Error" of their drops (distance and bearing of the simulated bomb impact from the target). During the two years I was at Naples Bomb Plot we scored over 5000 simulated bomb runs. Members of Naples Bomb Plot were also invited by the VAH Squadrons to visit their respective carriers and to fly a hop or two with them. I was lucky enough to be invited to take a short cruise aboard the USS Franklin D. Roosevelt with VAH-11. I only had one cat shot and one arrested landing, but that was the biggest thrill of all of my 22 years in the Navy. Sincerely: Kenneth C. Minick TDC USN(RET)
Fri, Apr 10, 2015 6:45 pm
History of RADAR Bomb Scoring
Tue, Apr 14, 2015 1:25 pm
The run would last 10 minutes from IP to release. Only the last part of the run was recorded on the plotting board. We would get a ground track after release to score the IBDA break-away maneuver and another release if it was a Large Charge with two bombs. At this time another crew would be departing the IP for the next run. Each run cost $10, 000. This was duplicated 24/7 on fixed, semi mobile, RBSExpresx and NIKE sites.
My next plan was shot down by JFK. To use the Polaris traking radar on nuclear subs to score. John asked " what the hell will they aim for ?" "Get this Renfro guy outta here before he does any real damage!"
So, what do we do with the score? The bomb is either over, short, left or right of the burst. This is coded into 6 numbers. We code the miss as CEP, circular error probability as plotted in degrees from true north. First three numbers are in degrees, the last in tens of feet. This is added to the daily additive which changes daily for security.
Now, between you and me ( no one in the world knows my secret ) I can " fudge " the results. Why would I do that ? Let's say an aircrew is on the verge of becoming a Select crew. This means $$$ to each crew member by the spot promotion. Crease the plotting paper over the ground track. This will shorten the miss by 100 feet per crease. To lengthen, put a pencil mark on the track, then erase. You have just added a hundred feet.
My own philosophy on bomb scoring is if you score a shack or bullseye it means they missed in real life because of all the errors in measurement.
Method, with Nike Hercules
Many Nike Hercules veterans commented (sometimes unhappily) about "bomb scoring" by the Air Force, using the Nike IFC equipment and personnel.
Fri, Apr 10, 2015 10:21 am
I'm the one that introduced the Army and National Guard to RBS. I lost track of the program in 1961 or 1962. I was planning to introduce air and ground jamming, did it ever get implemented ? The TTR was to control a TLQ-11 X-band jammer plus receivers, scopes, recorders, cameras etc. I was also involved with the RBS Express at the same time. It was a train fitted wth MPS-9 (modified SCR-584 ), M33 FCS, communications, maintenance, etc. equipment. Quite a project keeping In mind 400 Hz. was required in addition to being self contained. Up until this time RBS had only hand-me-down equipment. The Nike crews hated to see me arrive at a hot battery because they new they had to start working. The NationalGuard were combat ready every time I arrived.
How large was the potting board. I don't know, if I spread both arms out, my finger tips would probably reach the sides.
At the beginning of a bomb run after the go ahead, something like this is transmitted to the RBS site: "This is Expel 15 requesting a synchronized radar offset run on target Echo. Crew number S-32, operator Smith, J. E, rank O-4, equipment type Romeo, type of release automatic, bombing altitude 33,124, true air speed 436 knots, winds S at 15, W at 5, trail 6046 feet with a burst at 564 feet. Departing IP at 1545 Z, will call at 50 and 25 miles from release."
Thinking back, the ground track was about an inch per second, I may be way off on this. The run would last 10 minutes from IP to release. Only the last part of the run was recorded on the plotting board. We would get a ground track after release to score the IBDA break-away maneuver and another release if it was a Large Charge with two bombs.
Tue, Apr 14, 2015 12:25 am
True north to the USAF is toward the top of the plotting board. I discovered that after the first few runs were plotted as Gross Errors, ( over 5000 feet Circular Error Probability ), something was amiss. I visually spotted the aircraft and target so l knew these were not Gross Errors. So after correcting this problem by recalculating the target computer input trigonometric target functions, easier than moving the NIKE missiles to another point on the plotting board. What the new funtions did was erase missile battery coordinates when they occurred in the calculations and added the North Star with its offset from true north. I have never found a NIKE RBS site on the internet. Nor have I found a site for Military Brats that were in Germany from 1945 to 1950. My father was career USAF, 38 years total as Commander Aviation Cadets, JAG etc. In Germany he was on the War Crimes. I went to the first dependent school there. Of all the kids there at that time one should have started an internet site. Most probably gone, I am 80 years old now.
Tue, Apr 14, 2015 1:01 am
Forgot to comment on that. A 1000 Hz tone was transmitted over the radio about 30 seconds from bomb release. At the exact time of release the tone was terminated which lifted the stylus from the plotting paper. The stylus also recorded 3 second blips so an RBS plotting ruler could measure ground speed. The target was the center of the plotting board. Of course, the stylus recorded the aircraft track over the earth. The aircraft would typically perform defensive or evasive action during the run. If it interfered with the run after being notified to stop an Air Abort was declared. Same if it did not stop jamming the RBS radar. Most of the time we could track through the jamming. At least 30 seconds of steady ground track to score, was required before and some after release. If an abort occurred, the RBS would search for some way to blame the aircrew, and, they would try to blame it on equipment intermittent failure, weather etc. We on the ground very seldom had an abort of any kind.
comment by Ed Thelen Hmmmm - the target in the middle, tracking the bomber on the plotting board for at least a minute before simulated release- Bomber moving at about 7 miles/minute, bomb fall from say 32,000 ft. That must have been a large (area) plot !! Bomb fall from say 6 miles (ignoring air resistance I presume) According to http://www.gravitycalc.com/ it takes ANSWER: Object takes 44.4 seconds to fall 6 miles on Earth Bomb advances maybe 5 miles during the drop. That plotting board must have been at least 15 miles from center to edge. I really don't think you can resolve a pickle barrel at that scale ;-))
Method, with railroad train
Fri, Apr 10, 2015 6:40 pm
http://en.m.wikipedia.org/wiki/RBS_Express - RBS Express
Sun, Apr 12, 2015 9:20 pm
Mon, Apr 13, 2015 10:03 am
- For relocating, the dish was disassembled and the az-el drive/mount retracted into the van. I was never at the train when it was getting ready to move.
"Sacremento" - ? a fixed/permanent installation ?
Fri, Apr 10, 2015 6:33 pm
Sacremento December 1960/OA-215 Computer & Plotting Board
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Started April 14, 2015