0850 makes provision for shipping experimental
sonobuoys in this container.
But there are limitations:
(a) all the dangerous goods are contained within the aluminum body of the experimental sonobuoy described by drawings no. 200896, 200898, 200702, 200671, 200836 and 200837 deposited by Ultra Electronics Maritime Systems, a division of Ultra Electronics Canada Defense Inc. on Transport Canada's Transport Dangerous Goods Directorate file A 4069-0850;
(b) the sonobuoy contains a single UN0454 Igniter having a net explosive quantity equal to or less than 0.15 g;
(c) the sonobuoy contains a maximum of 2 cylinders of UN1013, Carbon dioxide, each having a capacity equal to or less than 0.120 L;
(d) the sonobuoy contains a quantity equal to or less than 40 "C" size lithium batteries that meet the requirement of paragraph (1) of Special Provision 34 of Schedule 2 of the Transportation of Dangerous Goods Regulations;
(e) the sonobuoy is packaged in the military performance specification plastic shipping container type CNU-239/E specified in the drawing 012-159-0009-00 deposited by Ultra Electronics Maritime Systems, a division of Ultra Electronics Canada Defence Inc. on Transport Canada's Transport Dangerous Goods Directorate file A 4069-0850;
This is a beacon transmitter that just transmits a narrow pulse in the sonobuoy frequency range. But, the signal requires a receiver with about a 150 kHz channel bandwidth.
Since the only information it sends is it's center frequency, probably one of a small list of possible frequencies and one of two possible duty cycles the process gain is extremely high.
During the Vietnam era there were airplanes circling over areas where ground based sensors were placed to relay the VHF sensor signals to a ground station (Wiki). This page was made because of the similarity of ground based intrusion sensors and sonobuoys. They both work the same way and both have the same reception requirements.
My guess is that today there is a satellite system doing the same thing. This system would receive in the 136 to 173 MHz range and use digital IF processing, similar to what's done in the HP 4395A combined spectrum network and impedance analyzer. If that was the case then it would be straight forward to have the ability for this receiver to receive not only sonobuoy signals but also the waveform used by the Black Box.
This makes sense in that the system would have world wide coverage without the need to have planes circling 24/7 like in Igloo White.The WiNRADiO MS-8118/WSB Sonobuoy Telemetry Multichannel Receiving System (WiNRADiO) covers 136.000-173.500 MHz (custom frequency ranges available) with an IF bandwidth of 30 kHz @ -6 dB.
They also have a WiNRADiO AX-61S Sonobuoy Telemetry Antenna that covers 135 to 175 MHz.
The G315i receiver can be ordered with an optional hardware wide band demodulator that's the same as in the sonobuoy receiver: WR-G315i Receiver Options or for the WR-G315e Receiver Options .
Note the black box beacon transmitter may be associated with the SEAL Delivery Vehicle (Wiki: SDV).
That would be perfect for receiving the Black Box signal (thanks to Chip Veres) for letting me know about the MS-8118. But this raises a new question, what else generates such a wideband signal?
The transmission frequencies of some black box units are: 164.5375 & 164.5875 MHz. Note neither of these is on channel 4 (164.50 MHz) and they differ by 50 kHz, not likely an accident.
3116471 Radio sonobuoy system, Jesse J Coop, Dec 31, 1963, 367/3, 367/5, 367/113, 367/101, 367/126, 367/115, 318/638 - In the present invention a multi-beam directional hydrophone is utilized in a radio sonobuoy system whereby an immediate quadrant location and an accurate distance measurement of a reflecting object from the multi-beam directional sonobuoy can be obtained from a single pressure pulse generated in the water area of interest. - DIFAR
3987404 Underwater Direction Finding System, Sanders, (filed: Nov 3 1967) Issued: Oct 19, 1976, 367/3; 367/125; 367/126 -
"An underwater direction finding system includes a pair of directional hydrophones and a compass in a novel arrangement which associates the signals from all three elements with a single subcarrier. Subsequent demodulation of the subcarrier signals in an airplane or ship then provides directional information directly referrenced to the earth's magnetic coordinates."
|US4078222||Nov 20, 1969||Mar 7, 1978||The United States of America as represented by the Secretary of the Navy||Direction determining apparatus|
|US4371957||Dec 12, 1969||Feb 1, 1983||Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence||Antisubmarine warfare system|
|US4604733||Jan 3, 1984||Aug 5, 1986||Westinghouse Electric Corp.||Apparatus for determining range and bearing|
|US4653033||Oct 4, 1984||Mar 24, 1987||Thomson-CSF||Goniotelemetry system|
|US4691305||Sep 5, 1985||Sep 1, 1987||The United States of America as represented by the Secretary of the Air force||Automatic attenuator for sonobuoys|
|US4872146||May 23, 1988||Oct 3, 1989||Canadian Patents & Development Limited||Method and apparatus for simulating phase coherent signal reflections in media containing randomly distributed targets|
|US4914734||Jul 21, 1989||Apr 3, 1990||The United States of America as represented by the Secretary of the Air Force||Intensity area correlation addition to terrain radiometric area correlation|
|US5859915||Apr 30, 1997||Jan 12, 1999||American Technology Corporation||Lighted enhanced bullhorn|
|US5885129||Mar 25, 1997||Mar 23, 1999||American Technology Corporation||Directable sound and light toy|
|US7088830||Mar 18, 2002||Aug 8, 2006||American Technology Corporation||Parametric ring emitter|
|US7109789||Jan 21, 2003||Sep 19, 2006||American Technology Corporation||Modulator—amplifier|
|US7224219||Sep 18, 2006||May 29, 2007||American Technology Corporation||Modulator-amplifier|
|US7564981||Oct 21, 2004||Jul 21, 2009||American Technology Corporation||Method of adjusting linear parameters of a parametric ultrasonic signal to reduce non-linearities in decoupled audio output waves and system including same|
Earth's Field Magnetic Detectors
Also see my Flux Gate patents web page.2252059
Method and a device for determining the magnitudes of magnetic fields,Gustav Barth, Priority Dec 24, 1936, Pub Aug 12, 1941 - rod fluxgate
Unbalanced magnetometer,Schmitt Otto H, Jul 10, 1951, 324/255, 340/870.33 - second harmonic
Detection system,Thaddeus Slonczewski, Bell Telephone Labor Inc, Nov 15, 1949, 324/246, 340/870.33, 324/254, 324/253 - moving parts
Magnetic field strength indicator- no moving parts
Magnetic field strength indicator
Cathode ray device
Magnetic field direction and intensity finder
Magnetic field detector - second harmonic magnetometer
Magnetic controlling device, Glennon James B, Maltby Wilson R, Sellman Albert H, filed Jun 25, 1941, pubMar 26, 1946, 340/850, 324/259, 340/551, 102/417
2644243 Control compass, George E Breeze, Russell I Mason, Us Navy, Filed: Nov 20, 1944, Pub: Jul 7, 1953, 361/280, 33/363.00Q - for use in sonobuoy, eliminates vertical component of Earth's mag field for more accurate mag bearing (for: DIFAR) 3526002
Magnebuoy,Ramond C Waddel, Filing date Mar 31, 1960, Publication dateAug 25, 1970 (maybe withheld secret), 340/852
The early Spilhaus Bathythermographs were based on a stylus marking a microscope slide blackened soot. This basic design went through many improvements. It was deployed on a line and recovered to get the glass slide. Note while each of these has a serial number and a custom made calibration chart for that serial number in order to convert the data on the glass slide to depth and temperature. That data was used to determine the Assured Range (AR) of a sonar system. Note the sound is bent downward when the water gets colder with depth and when a submarine on the surface is beyond the AR distance it is invisible to the sonar.
The Submarine Bathythermograph (SBT) is built into the sub and records depth and temperature on paper cards. The sound man will know from charts that contain BT data, as well as other data related to sonar, what to expect in the current operational area. But to get a more accurate picture a deep dive with a fresh BT card in the machine or dropping a BT sonobuoy (SSQ-36 , ST-1from the surface will give an accurate picture of the current conditions. A lot more info on BT in An Ocean in Common (Ref 4).2297725 Bathythermograph, Spilhaus Athelstan F, Submarine Signal Co, Filed: Aug 10, 1938, Pub: Oct 6, 1942, 374/136, 374/E01.3, 73/729.1 - marks smoked glass slide with pressure & Temp
2515034 Bathythermograph, William M Ewing, Allyn C Vine, Us Navy, Filed: May 27, 1944, Pub: Jul 11, 1950, 374/136, 73/300 - rapid response to temp & pressure (recording inside unit)
2629083 Expendable radiosonic buoy, Barkson Joseph A, Mason Russell I, Mcnary James C, Filed: Sep 21, 1944, Pub: Feb 17, 1953, 367/3, 343/709, 455/99, 441/33, 441/23, 343/705, 343/901 -
2703009 Bathythermograph, Ewing William M, Vine Allyn C, Filed: Nov 28, 1945, Pub: Mar 1, 1955, 73/178.00R, 346/120, 73/712, 73/742, 374/E01.3, 73/299 - for use on subs
2683987 Method of ascertaining unknown data, Earl W Springer, Filed: Jan 2, 1946, Pub: Jul 20, 1954, 374/100, 356/393, 73/584, 367/99 - the importance of depth v. Temp data for sonar. - uses optical comparison of a BT glass slide plot with a catalog of plots to get a rapid interpretation of the meaning in terms of SONAR.
3098993 Sonobuoy-bathythermograph system, Coop Jesse J, Jul 23, 1963, 367/134, 374/E01.3, 340/870.17, 340/870.6, 367/185, 367/3, 374/E01.4, 73/170.34 - sound output that can be heard by sonobuoy.
3119090 Sea depth determination air survey means
3135943 Underwater thermometric apparatus, Welex Electronics, - sets off a small explosion at a specified amount of change in temperature.
3273393 Bathythermograph, Spark Wallace R, Douglas Aircraft Co Inc, Sep 20, 1966, 374/136, 340/852, 73/170.34, 374/E01.3, 73/292, 367/134, 374/142 -
2402143 Parachute pack, Arenstein Gilbert H, Sec of War, Filed: Jun 7, 1944, Pub: Jun 18, 1946, 244/138.00R, 455/99, 343/709, 244/151.00B, 343/889, 441/11, 367/4, 116/26, 455/96 - for sonobuoys with antenna through center of parachute.
3441901 System for measuring sound velocity in water as a function of depth, Cawley John H, Schiff Daniel, Us Navy, Apr 29, 1969, 367/131, 367/134, 73/597, 367/89 - a sound projector, triggered by a surface ship sends a ping to the ships sonar which measures the time delay. Knowing the depth and horizontal distance to the probe allows a direct readout of the sound velocity.
Note in 1969 the ability to measure short time intervals was much poorer than today, so the length of the base line can be shortened from maybe 100 feet to something more reasonable like a yard so that the device could be permanently mounted on a ship or sub.
4215571 Expendable bathythermograph for use under ice, Ralph P. Crist, Secretary Of The Navy, Aug 5, 1980, 73/170.29, 374/E01.018, 374/E01.004, 73/300, 73/170.34, 374/136 - a housing for the (SSQ-36?) that floats up and when it hits the surface or the bottom of the ice releases the (SSQ-36?).
A water activated battery powers a GE 131 flashlight lamp
(1.3 Volts, 1.3 Watts, i.e. draws 1 Amp)
Stk. No. 6230-299-5653
Type J-2, with Water Activated Battery.
Spec. MIL-L-7396A(ASG) Application: Life Rafts
One Each Item No. 4
Contract No. AF 30(635)-23525
Fulton Mfg. Corp. Mfg/Contr., Wauseon, Ohio
A-1 A8- 8/61 Reinspection Date.......... 8/64
Light Sea Rescue Marker
Type J-2 MIL-L-7368A(ASC)
Part No. N-45A
Fulton Mfg. Corp.
Caution: Do Not Remove Plug for
|Fig 1 Box
||Fig 2 The Aluminum tube is to protect the
light housing from being broken and is supposed
to be in place when deployed.
|Fig 3 There are loose crystals in the
There is a small opening that shows up as a light
circle about where the rubber plug is located.
||5 vacuum tubes single
channel FM transmitter between 67 & 72 Mhz.
See Roswell Connection below where this was used with "disk microphones" on Project Mogul
CANADIAN LANCASTER - AN/CRT-1 SONOBUOY SYSTEM - drawing of aircraft equipment & buoy
Chapter 16 - SOFAR, HARBOR DEFENSE, AND OTHER SONAR SYSTEMS
Naval History - RADAR - MAD and CRT-1
CRT-1A: 67.7 to 71.7 MHz
CRT-1B: 62.9 to 66.9 MHz
Mechanical rotation of hydrophone (Ref 6)
||separate web page (Differences to -1 and
-1A? Let me know)
|not UK SSQ-20
|1950 start of: Sound Surveillance System (SOSUS)|
|AN/SSQ-15||Julie RO B-size|
||19 Nov 1964|
||19 Nov 1964|
The BT sonobuoy is an expendable thermal gradient measurement sonobuoy that operates on one of three or one of 99 Radio Frequency (RF) channels. It consists of a thermistor (Wiki) temperature probe that descends through the bottom of the sonobuoy canister producing a continuous reading of temperature versus depth. The thermistor temperature probe will descend to 1000, 2000, or 2625 feet, depending upon the sonobuoy selected.
10 to 6,000 Hz
||(replaced Julie explosive
active ping omni directional range only
replaced by SSQ-50
||replacedd by SSQ-41B
||31 RF Channels
10 Hz - 2.4 kHz
90 feet fixed depth
|SSQ-53A||90 or 1000' depth
1 or 8 hours
fitted with microprocessor controlled EFS capabilities,
with three depth selections [100, 400 or 1000 feet],
three operating time selections of 1, 3 or 8 hours,
99 vhf channels.
|SSQ-53D||Dwarf "G" size version of
|SSQ-53D||DIFAR only sensor, 90, 400
or 1000 feet, no CFS
5 Hz - 2.4 kHz
1/2, 1, 2, 4 or 8 hours
sea state 6
Additional hydrophone @ 45' for CSO
100, 200, 400 or 1000 feet
91.44 cm long
made by combining the
305 cm long
SSQ-53E & SSQ-57
adds CO hydrophone with directional units (replaces SSQ-57)
CFS Rx - single channel UHF
Tx - 96 selectable frequencies (136 - 173.5 MHz), 1W
90, 200, 400, 1000 Ft.
10 to 10,000 Hz
See separate web page
||Command Function Select
Electronic Function Select
96 chan 136.000 - 173.500 MHz
CW Out: 6.5, 7.5, 8.5 or 9.5 kHz
|SSQ-77B||" more hydrophones, 2
depths, 2 beams
||" adds RF command function selection|
||advanced EER ADLFP sound
used with: ADAR sonobuoys like SSQ-53F, SSQ-77C and SSQ-101
This is typically dropped from a friendly sub hunter aircraft in order to send one of a small number of predetermined messages to a submerged sub. It uses audio tones around 3 kHz.
Like the CRT-1 Sonobuoy, ST-1 Bathythermograph and the T346/SRT SOS buoy is 3" in diameter so could be used from the Submerged Signal Ejector on a sub.
Submarine Communications: "Signal, Underwater Sound (SUS) Mark 84" US Navy Training Film -
Mk-84 Mod 0
Got this on eBay with a fake nose cone that's been removed. It's just the tail shell, but has markings:
DOD Code: SA-06
Date Pkgd: (blank)
Ser. No. (blank)
Wt. 6.5 Lbs. Nom.
SUS MK84 MOD 0
There are 4 tapped holes for attaching the transducer/electronics package. Adjacent to these holes are 4 holes 3/8" dia (total area: 0.44 sq in) that are the inlets for the water activated battery that's inside this tail section. The center hole at the back is 7/8" ID (total area: 0.61 sq in, i.e. much larger than the inlet hold area. Why?).
(MK-84 MOD 1 SUS uses 3.3 and 3.5 kHz audio to generate 5 codes as messages to a sub.)Air to sub communications.
Drift - Compute - Reset
PDI: BDHI: Marker 1 to 6, GTP: Marker 1 to 6 Insert
ASA-20 or AQA-1 ASA-20 or AQA-1
A-B: 1 to 6
A: Off to 6 Data Release B: Off to 6
|ASA-31 Julie Control Panel
Deinterleaver Technology for Future ESM systems, Dec 1992 NSWC - each pulse received from a single emitter can be agile in frequency, pulse width, pulse amplitude, pulse repetition interval, but not direction. So using the Pulse Descriptor Word from the ESM sensor a future deinterleaver can sort out each emitter and differentiate between friendly and hostile emitters. ESM systems mentioned:
IBM Associative Comparator
Anaren ESM Processor
ALQ-32 Inner Processor
Instantaneous Frequency Measurement (IFM) receivers are part of the ESM sensor. But this type of receiver can have problems with two signals at the same time or with a CW signal anywhere in it's frequency range. The proposed configuration is to use narrow band receivers (many channels) and for each channel two paths, one for angle of arrival and the other for characterization of the received signal.
Sippican Ocean Systems SSXBT Model ST-1
This is one of a number of devices that can be launched from the 3" launcher.
Fig 2 Label
Fig 1 3" dia x 36" long
Some Guidelines for the Submarine-Launched Expendable Bathythermograph (SSXBT) System (DTIC Oct 1981, 50 pages) The AN/BSQ-23 (older) and AN/BQH-7 (newer) have higher incidence of failure than the Bathythermographs used abord surface ships. This document is to help in recognizing when they have failed. Typically used to measure ocean temperature v. depth in 100 foot intervals down to 2,500 feet. This can be used a part of the launch solution for the Mk 48 torpedo. It seems the sub needs to be at the surface to launch the ST-1. Because of the hydrodynamics of the ST-1, it's rate of decent is known, it's possible to know the depth by the time since it was on the surface. It should take 2 minutes 58 seconds to go from the surface to 2,500 feet. If the sub enters a new ocean front (see map on pdf pg 18) the BQH-1 graph will show a change. That can be compared to the SSXBT data to confirm correct operation of the SSXBT. The appendix has 21 example plots each showing a different problem.
4518915 Test device for expendable bathythermograph, Philip G. Danforth, Thomas G. Bucko, Kenneth R. Galliher, Joseph T. Lucia, Richard L. Miller, Timothy B. Straw,
Secretary Of The Navy, May 21, 1985, 324/750.01, 324/762.01, 374/E15.001, 374/134 - "...to provide a simulator for testing and calibrating a wide variety of XBT systems used on board surface ships and submarines...."
The BQH-1 Depth-Sound Speed can be used as a check on the SSXBT. This plots the speed of sound (time delay for a fixed distance) v. depth (water pressure). Either temperature or sound speed units can be used, it's best to use temperature units to allow matching to the SSXBT data.
AD-758 085, Engineering Evaluation of Depth-Sound Speed Measuring Set AN/BQH-1 Manufactured by Dyna-Empire Corp. Garden City, New York. Contract NOBSR-75772, Navy Underwater Sound Laboratory, New London, Connecticut, 10 March 1961.
ConstructionSince the sonobuoy has a cylindrical ( 4-4/7" O.D.) shape it makes sense to have the electronics in the form of cylindrical modules that can be stacked end to end. These modules are about 2-3/4" O.D. and have a circular connector around the outer edge. For use as an outdoor intrusion detector the hydrophone is replaced with a geophone (Wiki), or other sensor like used to listen for the RF generated from spark ignition engines.
The barrier would consist of a 20,000 air dropped listening devices combined with 240,000,000 Gravel mine and 300,000,000 Button mines and 19,200 Sadeye cluster bombs at a cost of around one billion dollars a year, not including 1.6 billion dollars for research and development, and the construction of a 600 million dollar command center in Thailand.
It's designed to be air dropped with a drag chute and get hung up in the trees. There is a central tape whip and four ground plane tape whips each 17" long.
which is a quarter wave at about 190 MHz.
The central gold colored thing is the microphone. Note all the holes in the front to let sound it and protrct the microphone from tree limbs.
This is a battery type I don't recognize. If you know about it please let me know what it is.
|Sound Observer (Locator)
It's identical to the mike in the acoubuoy.
This is the same mike that's in the photo at left with
the question mark. The 5 socket connector is marked:
The contacts are numbered 1, 2, 3, 4 (but no 5).
There's a knurled and slotted screw head on the back that can be unscrewed about 1 turn, maybe to normalizing the pressure inside to match atmospheric.
See RT-1185 for a similar application.
An eBay ad showed the GSQ-171 beside the USQ-46
receiver. It has what appear to be Vietnamese markings.
What is this: Contact me
1154272 Marine Mine, Emil Senger, Raimund Sauter, Sep 21, 1915, 102/408 - a plug dissolves after a predetermined time scuttling the mine
1308003 Apparatus for detecting and indicating the presence of submarine boats, G.E. Elia (Italy), June 24, 1919, - raises a flag when sub entangles net
1426337 Signaling apparatus for detecting submarines, Sperry Elmer A, Filed: Jul 9, 1917, Pub: Aug 15, 1922, 455/97, 441/11, 343/709, 174/138.00R, 294/111, 313/553, 114/240.00R, 313/243, 102/402, 174/77.00R, 455/99, 174/153.00R, 343/896, 200/83.00R - when net is entangled by a sub the buoy sends a radio signal
2629083 Expendable radiosonic buoy, Barkson Joseph A, Mason Russell I, Mcnary James C, Filing: Sep 21, 1944, Pub: Feb 17, 1953, 367/3, 343/709, 455/99, 441/33, 441/23, 343/705, 343/901 -
1471547 Production of submarine signals and the location of submarine objects, Chilowsky Constantin, Langevin Paul, May 19, 1917 (W.W.I) Oct 23, 1923
367/87, 367/174, 89/41.8, 89/41.7, 310/337 - uses the term "ultra-sonorous" 50 kHz to 200 kHz
Signaling apparatus for detecting submarines,Sperry Elmer A, Jul 9, 1917, Aug 15, 1922, - triggered by net 455/97, 441/11, 343/709, 174/138.00R, 294/111, 313/553, 114/240.00R, 313/243, 102/402, 174/77.00R, 455/99, 174/153.00R, 343/896, 200/83.00R
Method and apparatus for the detection of submarines by airplanes,Constantin Chilowsky, Apr 25, 1941, Oct 24, 1944, -
367/120, 102/419, 244/137.1, 367/130, 102/427, 434/6
Method and device for establishing communication between aircraft in full flight and the ground,Chilowsky Constantin
2397844 Signaling apparatus, Wallace W DeWhurst (RCA) Apr 2, 1946, 367/3, 138/89, 114/198, 455/99, D10/107, 441/11, 73/322.5 - sonobuoy
2402391 Submarine detection, De Witt R Goddard, Rca Corp, Filed: Aug 30, 1943, Pub: Jun 18, 1946, 367/115, 124/51.1, 89/1.51, 367/112, 221/279 -
2420676 Submarine signaling apparatus, Robert E Peterson, Jan 23, 1943 (W.W.II) May 20, 1947, 114/23, 367/150, 114/21.1, 116/27, 181/402, 114/21.3 - uses the term "superaudible frequencies"
Calls:2828475 Remote Control or Measurement Indicating Means, (Sec of Navy), Mar 19 1958 - Sonobuoy that adds direction to sound in addition to just omni directional listening
1731127 Signal Control System (railroad), Oct 8 1929
1859423 Sound Recording - multiple needles for echos
2039405 Remote Metering System (AT&T) -
2066156 signaling Means, Apr 25 1929, - relative motion
2206036 Distance Measuring Apparatus and System, J. Herson, Jly 2 1940, - optical aircraft altitude blind landing
2329612 Apparatus for Training Aircraft Pilots, G.E. Hill et al, Sep 14 1943, - includes real time position output
2332523 Ground Track Tracer and Landing Recorder, E. Norden et al, Oct 26 1943, - servo controled pen recorders
2358793 Navigation Instruction Device, C.J. Crane, Sep 26 1944, - scaled movement of student over floor
2373560 Sound Recording Method and Apparatus, J.M. Hanert (Hammond Inst Co), Apr 10 1945 - adding vibrato
2375004 Training Apparatus, May 1 1945 - sound and recoil of a real gun
2444477 Automatic Miniature Radio Range (A-N), 1948 - used with pen recorder
2452038 Photoelectric Radio Compass Trainer Control, 1948 - based on scale map
2459150 Interception Trainer 1949 - call "Link" patents: 1825462, 2099857
1610779 Signaling apparatus, Gen Electric, Dec 14, 1926 - an underwater device that sends a signal when it receives a signal. aimed at ship positioning, but could also be used for sub detection? A number of patents reference this on.
|3372368||March 1968||Dale et al.|
|3093808||June 1963||Tatnall et al.|
|3140886||July 1964||Cotilla et al.|
|3309649||March 1967||Ballard et al.|
These were originally called Magnetic Airborne Detectors (Ref 3) and was developed by the NDRC (Wiki) and was paired with the use of sonobuoys.
Maximum range 1 to 2 thousand feet. I'm guessing the range includes the depth of the sub, so the deeper the sub the more likely MAD will miss it.
When I lived in Mountain View it was a very common sight to see a P-3 Orion (Wiki) landing or taking off from Moffett Field Naval Air Station (Wiki). They had a "stinger" on the tail that held the magnetic anomaly detector. Here's a Youtube video of the MX-1361/ASQ-8 MAD
It appears to have 3 coils, each about 4" in diameter by 2" thick made by TI mounted in 3 orthogonal directions (X, Y & Z)
The ASA-65 is the motion compensator for the ASQ-81 MAD system. That's to say that any motion of the P-3 will cause the X, Y & Z components of the Earth's magnetic filed to change. To back that out three coils can be placed over the magnetic sensors and those coils driven from the output of the ASA-65.
When testing a MAD a small portable "Gamma Slinger" is used that generates a known (1045' c.g.s units) rotating magnetic field.
1045 Gauss converts to 104,500,000 nanotesla. Since the Earth's field is about 50,000 nanotesla the Gamma Slinger is about 2000 times as strong as the Earth's filed.
It's probably made using a modern permanent magnet rotated on a shaft by a clock work where the shaft and clockwork are all non magnetic. This test device could be used on the flight line to check out the MAD system.
It can easily be detected at over 20 feet using the ASQ-81.
The AN/ASQ-208 is a digital processing type MAD system.The ASQ-1, ASQ-1A, ASQ-3 and ASQ-3A was used in conjunction with the CRT-1 sonobuoy in W.W.II.
Ref pg 302, Chapter 16, SOFAR, Harbor Defense, and other SONAR Systems, Naval Sonar, NAVPERS 10884, 1953
The ASQ-3A was used as the basis of an magnetic survey of the world.NOL vector airborne magnetometer type 2A (VAM-2A)
Ref: Airborne Geomagnetic Surveys by the United States Hydrographic Office, Henry P. Stockard, USN Hydrographic Office, NAVIGATION, Journal of The Institute of Navigation, Vol. 4, No. 8, 1955, pp. 320-323. modified to use the Vector Airborne Magnetometer type 2A (VAM-2A)
The Pave Mace system that used the Black Crow MAD sensor was optimized to pickup the magnetic filed from ignition system in Vietnamese vehicles. (link to external web page with photo of it). The plate to the side of the dome with 3 rows of holes along the top and 3 more rows of holes on the bottom has the feel of a slot antenna for VHF or UHF signals, so more of a radio system than a MAD system. If you have any definitive information let me know.
It's not clear if this is a magnetic system or a VHF/UHF radio system.
Magnetic Anomaly Detector (MAD) Patents2361177 Method and apparatus for the detection of submarines by airplanes. Constantin Chilowsky, Filed: 25 Apr 1941, Pub :24 Oct 1944, 367/120, 102/419, 244/137.1, 367/130, 102/427, 434/6 - Referenced by 35 patents - not MAD by rather audio
Apparatus for responding to magnetic fields,Vacquier Victor V, Gulf Research Development Co, filed: Jul 21, 1941,
324/253, 102/417, 33/361, 318/647, 324/326, 324/345, 324/255, 340/870.33, 102/427The following detectors are towed on a cable from a plane flying at 300 feet above the water:
This is THE MAD patent and is referenced by a very large number of others.
2379447 Antisubmarine device, Lindsey Henry A D, Jul 3, 1945, 102/417, 102/212, 340/551, 324/247, 324/67, 307/652, 324/258, 340/552
2404806 Submarine detector, Lindsey Henry A D, Jul 30, 1946, 340/850, 102/402, 324/247, 324/331
System for detecting magnetic masses, Frank Rieber, Interval Instr Inc, Jul 29, 1947,324/247, 324/331, 322/1, 324/257, 322/59, 340/870.32 2549857
Cable-suspended aerodynamic body,Schonstedt Erick O, Apr 24, 1951, 324/260, 324/262, 114/24, 244/3, 74/5.00R, 324/331, 324/246, 33/397, 33/366.11
Orienting mechanism for magnetic detector devices,Murphy Paul M, Mar 24, 1953, 324/253, 318/647, 324/246, 324/331
Compensated magnetometer, Richard Evans Chauncey, Dec 7, 1954,324/253, 324/345 - uses term " magnetic anomalies"
You see this in movies like The Hunt for Red October or Crimson Tide.
3771115 Simulated submarine target apparatus, McLinden Hugh, - a viscous, gelatinous material having metalic particles suspended in it, is ejected by the sub to form a hollow bag-like structure which is filled with water.
2901997 Sound generator, Arthur H Brooks, Sep 1, 1959 (14 year delay), 116/27, 116/137.00R, 102/418, 367/1 -
3194207 Underwater sound sources, Dunne Brian B, Gen Dynamics Corp, Jul 13, 1965, 116/27, 367/142 - alectric motor driven noise maker + flotation device, cylindrical shape (torpedo tube or smaller?)
4194246 Noisemaker beacon, Ralph P. Crist, Secretary Of The Navy, Mar 18, 1980 (32 years delay), 367/1, 441/22, 441/12 - 10 to 100 kHz output
5117731 Tactical acoustic decoy, Mark A. Mendenhall, Secretary Of The Navy, Jun 2, 1992, 89/1.816, 102/348, 367/1, 102/501 - mounts on ship and jamms infrared, sonar & microwave.
6252822 Countermeasure device with air bag hover system and pressure compensated acoustic projectors, Robert J. Obara, Secretary Of The Navy, Jun 26, 2001, 367/1 - uses compressed air for both depth control and noise making
Maybe called sonar counter counter measures was a type of sonar that was difficult for an enemy to hear.
A hydrophone (Wiki) is an underwater sound sensor. On purpose I did not call it some type of microphone because that would imply it can only respond to sound within the frequency band which human ears can hear. So, I think, sensor (Wiki) or transducer (Wiki) are better terms to use. The key reason for that is most SONAR (Wiki) involves ultrasonic frequencies.
An early piezo electric material used for hydrophones was Rochelle Salt (Wiki) which can be made from ingredients from the grocery store using instructions from YouTube. Since it's water based, getting water on the crystal will dissolve it, so maybe not idea for an underwater application. Barium Titanate (Wiki) is another piezoelectric (Wiki) material used for hydrophones. Although know in the W.W.II time frame, Titanium was not readily available in war time, so Magnetostriction (Wiki) was used for hydrophones early in W.W.II, like used on the CRT-1 sonobuoy.
See my Magnetics web page for an example of Terfenol-D material.
|Hydrophone, U. S. Navy
Harbor Detection, Sonic, NT-51038F; P/O type JR-1 Harbor
Sensitive listening, frequency range 1 - 20 thousand cycles per second; with 8 Rochelle Salt Crystal Doublets each approx. 3" x 2" x 1", in metal frame w/matching transformer to 25 ohm line, in Castor (?) Oil, encased by heavy rubber jacket 56" long x 2 1/2" in diameter; with 9 foot rubber covered cable 1/2" O.D. w/2 flexible copper wires insulated, plus 2 steel strain wires; to be used down to 400ft. depth while withstanding high pressure explosion waves. Mfg by Brush Development Company.
||Fig HP2 Transformer
The Black and Green terminals are physically in line.
The White wire is not an electrical connection but rather is where a couple of steel cables attach for supporting the weight of the hydrophone.
It's not clear what this is.
|HP 4395A Plot 1 Hz to 20
kHz RBW: 1 Hz, True RMS detection, 16 averages:
||HP 4395A Plot 1Hz to 20 kHz
RBW: 1 Hz, True RMS detection, 999 averages (54.6 hours):
|HP 4395A Z transform
Impedance Real & Imaginary
||HP 4395A Z transform
Hydrophone Impedance Smith Chart with Marker List
Their early work with Piezoelectric
was for microphones and speakers used in air.
Found this on eBay but the photos and description were not at all clear.
Let me know if you have any information on this hydrophone assembly.
Box label (Fig 1):
Hydrophone and Retainer Assembly
Hazeltine Corp Mfg/Contr
Sensitivity Minus _____ db
6 EL SH HYD
(6 element small hydrophone hydrophone?)
Cable can: 4" dia x 5-3/8" high
This is smaller than an A Size sonobuoy (4-7/8").
Maybe fits inside an A-Size?
Hydro Cup: 2" OD x 5" high
Cup holds 5 hydrophones + cup-end hydrophone
for 6 total.
Fig 1 OEM Box
5132940 Current source preamplifier for hydrophone beamforming, James A. Culbert, Hazeltine Corp, 1992-07-21 - listening buoys
2891232 Hydrophone for directional listening buoy, Heinrich O Benecke, 1959-06-16 -
2898589 Hemispherical acoustic phase compensator, Abbott Frank Riley, 1959-08-04 - makes use of a miniature replica
3037185 Sonar apparatus and components, Gerhard H Dewitz, Cgs Lab Inc, 1962-05-29 - "In one embodiment of this invention, which will be described presently, a scanning system is provided which does not depend upon mechanically moving parts for controlling the direction of the transmitted beam or the direction of greatest sensitivity of the receiving apparatus, and which permits continuous high speed scanning over any desired area." i.e. beamforming
3064235 Audible broadband sonar monitor, Keith E Geren, 1962-11-13 - a broadband ( kHz to 100 kHz) hydrophone driven receiver with special signal processing for hearing "single ping" sonar at an unknown frequency
3116471 Radio sonobuoy system, Jesse J Coop, 1963-12-31 - directional sound receiving beam coupled with magnetic compass do give directional information DIFAR
3281769 Transducer apparatus, Theodor F Hueter, Honeywell Inc, 1966-10-25 - probably for underwater locator beacon since "for use at extreme depths."
3559160 Spatial surveying and target detection system, Bradshaw Burnham, US Secretary of Navy, Filed: 1963-11-07, Pub: 1971-01-26 "10,000 hydrophones", tubes SOSUS?
3903407 Method for correlating frequency-modulated signals, Bradshaw Burnham, US Secretary of Navy, Filed: 1963-12-11, Pub: 1975-09-02 - photo-optical, SOSUS?
3905320 Low frequency homing system, William J Mueller, US Secretary of Navy, 1975-09-16 - homing system for torpedoes "The low frequency homing system of this invention utilizes lines of hydrophones or transducers spaced along the port and starboard sides, and along the top and bottom sides of a torpedo."
2409632 Guiding means for self-propelled torpedoes, Robert W King, AT&T Corp, 1946-10-22 - active ultrasonic SONAR
4423494 Beam steerable sonar array, Kenneth W. Groves, John D. Lea, Sperry Corp, 1983-12-27 -
6088299 Vertical hydrophone array, Louis W. Erath, Phillip Sam Bull, Syntron Inc, 2000-07-11 - seismic exploration cable includes time delay elements: "traveling wave antenna"
While studying the MH370 disappearance and search (March - April 2014) and in particular the 37.5 kHz ultrasonic pings from the Cockpit Voice Recorder (Wiki: CVR) and the Flight Data Recorder (Wiki: FDR) generated by the Underwater Locator Beacon (Wiki: ULB). This lead to the SOFAR channel (Wiki) and the thermocline (Wiki). A way to determine the depth of the thermocline is to drop an SSQ-36 (see SSQ-36 above) or other Bathythermograph such as the SSXBT (Wiki: BT). Note that the maximum depth of the SSQ-36 is 800 meters, not the center of the SOFAR channel which might be at 1000 meters, but low enough to be in the channel.
2587301 Method of sound transmission, Ewing William M, (Wiki), Us Navy, Filed: Nov 16, 1945 (7 year delay), Pub: Feb 26, 1952, 67/127 - "sound channel" , Fig 7 map showing listening staations: Aleutian Islands, Kurie Islands, Marinas, Saipan Islands & Midway. Explosion set for 675 fathoms.
2601245 Underwater signaling device, Charles F Bowersett, Filed: Jan 30, 1948, Pub: Jun 24, 1952, 181/142, 102/229, 181/125 - contains explosives
2760180 Long range explosive sonobuoy, George Sipkin, Filed: Oct 6, 1949, (7 year delay), Pub: Aug 21, 1956, - explains sound channel
It turns out that a stock sonobuoy can not hear the 37.5 kHz ULB since the highest frequency they can hear is 20 kHz (see DIFAR above). So a stock sonobuoy can not be used to find the CVR or FDR. But all the information about sound propagation in water is applicable to normal sonobuoy operation.
Note that military passive SONAR (Wiki) is designed to pick up the sounds generated by surface ships, submarines and torpedos (maybe 10 Hz to 20 kHz), not aircraft black boxes at 37 kHz. This frequency range does include a lot of sea life so a sonar man needs to know what they sound like, or his computer knows. If you rub your thumb and index fingers together you generate an ultrasonic sound, like that used by Bats, in the 30 kHz region but no normal audio.
Maurice Ewing (Wiki) who discovered the SOFAR channel (Wiki) figured out that the speed of sound vs. depth would cause sound to be "piped" if it was in the SOFAR channel rather than being omnidirectional if not in the channel. He extrapolated that idea to the atmosphere where the speed of sound vs altitude curve has the same shape as the one for speed of sound vs depth in water and so there should also be an atmospheric channel ( it turned out to be at about 50,000 feet whereas the ocean channel is at about 1000 meters deep). By putting microphones (in the 1940s the state of the art microphone technology was the Disk Microphone (used by Orson Wells - Wiki), or disk for short like we now say radio instead of Radio Receiver) in the channel you can hear sounds from very very far away that you can not hear any other way. Disk microphones are called "spring microphones" on eBay. For example rocket launches or atomic bomb testing.
Richard Muller Physics Lecture 11 - Waves 1
Wiki: Sofar bomb - Naval Airborne Ordnance NAVPERS 10826-A (Aircraft Reference book 17) describes the SOFAR bomb on pages 195 & 196 as "a 4-pound cylinder casing carrying the explosive, and a head which enables the operator to select one of the six possible depth settings between 1,500 and 4,000 feet." There is a Pacific ocean map showing receiving stations at Point Arena and Point Sur on the California coast and at Kaneone in the Hawaiian islands.
In the book Principles of Underwater Sound by Robert J. Urick (Reference 10) there is an example of the SOFAR bomb on page 415.
CommunicationThen I watched the UC Berkeley Physics 10 - Lecture 11: - Waves I (YouTube, Text) by Richard Muller (Amazon). It turns out that the Project Mogul (Wiki 1947 - 1949) used the bulk of a CRT-1 sonobuoy. They replaced the hydrophone with a string of "Disk Microphones" that was 657 feel long. He also mentions SOSUS and "Hunt for Red October" in passing. The SOFAR bomb was used by W.W. II pilots downed in the ocean. They would throw this hollow metal sphere (SOFAR bomb aka: SOFAR Sphere (Wiki)) into the water and it would sink. After about 5 minutes it would reach about 1000 meters depth and implode. The implosion had the energy of about 2 pounds of TNT. The shore based SOFAR stations would note the time of arrival and triangulate the location of the implosion. Later the Signals (underwater sound) Mk 22 Mods 0 and 1 were developed to work with the shore stations. If an enemy captured one of these SOFAR bombs and cut it open it would be very unlikely that they could determine what it was or how it was used.
Problem: In the sofar method of aviation rescue, a downed aviator drops a 4-lb explosive charge set to detonate on the axis of the deep sound channel. ow far away can the detonation be heard by a nondirectional hydrophone, also located on the axis of the deep sound channel, at a location of moderate shipping in sea state 3?
Solution: (detailed description of calculation) 4,000 miles.
When Project Mogul flight No. 4 crashed outside Roswell the Air Force reported that "flying disks had been recovered" from the wreakage, but the local paper reported it as a "RAAF Captures Flying Saucer". Note the change from plural because there were a large number of disk microphones to singular Flying Saucer".
See my Western Electric 387W Disk Microphone web page for an example of a disk microphone. Note eBay search term "Spring Microphone".
The Wiki page Roswell_UFO_incident - has an image from the Roswell Daily Record, July 8, 1947. The main headline is: "RAAF Captures Flying Saucer On Ranch in Roswell Region". The subheading is "No Details of Flying Disk Are Revealed".
This web page was started because of the connection to Vietnam era seismic detectors (outdoor intrusion alarms). But I still have not determined which sonobuoy was the source for the 2-3/4" diameter cylindrical components of the GSQ-160, if you know please tell me.
In the official Air Force book "The Roswell Report - Fact vs. Fiction in the New Mexico Desert - Headquarters United States Air Force - 1995 - ISBN 0-16-048023-X (free on line as roswell.pdf) - 993 pages see attachment 32, "Report of Findings on Balloon Research", chapter Project MOGUL, pdf-Pg 303 that describes the underwater sound channel and the idea by Dr. Maurice Ewing (Wiki) that there might also be a sound channel in the atmosphere and how to exploit that idea as Project Mogul (Wiki).
A Google Patents search on inassignee:"Gen Mills Inc" balloon will turn up many patents related to the new type balloon good for high altitude
Balloon construction,Winzen Otto C, Gen Mills Inc, Apr 2, 1948 - key is replacing rubberized fabric with polyethylene (Wiki)
Fast rising sounding balloon,Isom Langley W, Aug 16, 1948 - key non elastic material.
2767940 Balloon with strengthening elements, Donald F Melton, General Mills Inc, Filed: 1953-11-04 -
2767941 Seam for gored balloons, Frederick J Gegner, Alan A Reid, General Mills Inc, Filed: 1953-11-04 -
In the book An Ocean in Common: American Naval Officers, Scientists, and the Ocean Environment (Ref 4) they mention that the sound channel in the Atlantic ocean is 4,000 feet but in the Pacific it's at 2,500 feet. (page 173).
June 2018: In the book UFO Crash at Roswell: The Genesis of a Modern Myth edited by Project Genetrix (Wiki) balloons carried 600 lb. cameras. Ran 1955 to 1958.
Constant altitude balloon, William F Huch, General Mills Inc, Filed: 1952-02-15, Pub: 1954-01-19
2606443 Exploration of troposphere stratification, George W Gilman, Bell Labs, Filed: 1946-06-14 - shows existence of sound channel, although not called that
3070335 Automatic lift augmentation for balloons , Leland S Bohl, William F Huch, Edward P Ney, John R Winckler, Secretary of the Navy, Filed: 1959-08-04, Pub:
1962-12-25 - has the feel of Skyhook balloon (Wiki) flies at 100,000' (harder to shoot down)
3369774 Balloon envelope structure, Jr Arthur D Struble, Filed: 1961-08-02 -
also see: Radiosonde and New UFO Information April 2014
There are many similarities with the CRT-1, but . . .
It looks like mid 1960s (date code, TO-3 power transistor in power supply, 1xx and 3xx tubes).
Someone has scratched SONOR on one of the sheet metal covers with an arrow pointing down. This implies it's an active pinging unit rather than a passive listening only unit.
That is reinforced by the large space for batteries.
This is not mine. Photos and information supplied by Michael, VK4ZKT
UnKS Fig 1
UnKS Fig 2 Tubes may be 12AT7,
not low voltage like in the CRT-1.
UnKS Fig 3
UnKS Fig 4
6856578 Underwater alert system, Daniel J. Magine, Kevin D. Kaschke, Feb 15, 2005, 367/134 - Ocean Technology Systems Diver Recall System DRS-100?
3" Launch Tube devices top to bottom:
T-347/SRT Buoy, Radio Transmitting - launched from submarine
Vaisala RD93 GPS Dropsonde - launched from airplane
SUS: Signal Underwater Sound - launched from airplane
Sippican Ocean Systems SSXBT Model ST-1 Bathythermograph -launched from submarine
aka: Submerged Signal and Decoy Ejectors (SSDE)
Maritime.org - 12-4-01 Submerged Signal Ejectors - 6" internal diameter:
These are similar to 100mm diameter torpedo tubes are probably are located in torpedo rooms. These tubes can be used to launch various devices that fit the 100mm (4") tube.
Countermeasures, emergency beacons, signal flares, small explosive charges and probably a Bathythermograph (would require a way to handle the trailing wire) . . .
T-347/SRT Submarine Rescue buoy that transmits SOS SUB SUNK SOS is about 3-1/4" dia x 40-1/2" long and can be launched using the SSE.
Ref 8 mentions a 3" signal/decoy ejector (pg 69 photo of Bathythermograph & its terminal) that can be used for the Submarine Launched One-way Transmitter (SLOT)(pg 70). In the Glossary (pg 308) "usually 3-inch".
So are there two different small launch tubes, i.e. 3" and 4" or has one of these become a standard? let me know
2710458 Underwater acoustic decoy, Reed Donald G, Sec of Navy, Filed: Jun 14, 1945 (10.0 year delay), Pub: Jun 14, 1955, 434/6, 114/20.1, 367/1, 434/25 - passive SONAR training device
Fig 1: either 3x32" or 4x43", most likley 3x32"
Fig 9: either 3x24 or 4x32"
This may or may not be launched from a sub.
2981927 Underwater sound transmitter, Vaughn G Mckenney, Sec of Navy, Filed: Apr 4, 1946 (15 year delay), Pub: Apr 25, 1961, 367/1, 455/18, 114/20.1, 360/6 - returns SONAR pings at same frequency but offset in time (very similar to RADAR countermeasures).
Fig 1 shows a length/diameter ratio of 11.5, so if 3" dia then length is 34", if dia is 4" then length is 46".
Since a yard or meter shows up as a practical length then I'd assume this is a 3 x 34" device.
Mentions: 2793589 Buoyancy control device, Atchley Raymond D, Filed: May 3, 1944, (13 year delay), Pub: May 28, 1957, 102/414 -
5003515 Submarine emergency communication transmitter, Albert S. Will, Frank C. McLean, Sylvan Wolf, Samuel H. Kauffman, John C. Hetzler, Jr., Charles A. Lewis, George E. Maxim, Secretary Of The Navy, Filed: May 28, 1964, (27 year delay) Pub: Mar 26, 1991, 367/131, 367/145 -
Image flipped so that it's oriented as if in the water. There are 7 drop bombs which are released by explosive bolts and they explode after 20 seconds so that their depth will be controlled (probably within the sound channel (see Roswell Connection above). If the sink rate was the same as the Mk IX depth charge (15 fps) then after 20 seconds it would be down to 300 feet which is too shallow to get into the SOFAR Channel (Wiki). I suspect the time delay is really much longer to that the drop bombs get into the SOFAR Channel.
The timing of the drop bomb release translated into one of a number of coded messages.
The length/diameter ratio is very small so will not help to determine its dimensions.
5044281 Submarine flare with vertical attitude determination, Peter Ramsay, Brian W. Whiffen, Gerald M. Bushnell, Victor Nanut, Robert C. Czigledy, Robert J. Swinton, Maxwell J. Coxhead, Timothy R. Clarke, Australia, Sep 3, 1991, 102/340, 102/224, 102/351, 102/357, 102/354 -
The length/diameter ratio is 12.67, so: 3" x 38" or 4" x 57", seems to indicate it's 3 x 38".
Bombshell: The Hedy Lamarr Story - IMDB - Claims that the Navy used her invention on DIFAR sonobuoys in the RF link back to the airplane. The reference cited is:
Which no longer is on line and archive.org does not have a copy.
But that's a false claim since the link back to the aircraft is non encrypted. and doesn't need to be before the existence of satellites. There's no enemy to hear the transmission. Even today with satellites it's questionable if there's any value in encrypting the link.
ASW To Catch a Shadow - Anti-submarine Warfare, P-3 Orion, USS Scorpion 20850 HD - 29 minutes
Goblin on the Doorstep - ASW Anti-submarine Warfare 20870 HD - 29 minutes -Collecting microscope slide from early Bathythermograph,
ASW: Tracking the Threat 1982 US Navy Training Film; Anti-Submarine Warfare - 23 min - Launching Bathythermograph -
BT data after launch of BTU.S. NAVY SONOBUOY INDICATOR GROUP AN/AQA-1 ANTI-SUBMARINE WARFARE FILM 51114 (28:53) - 17.5 minutes @2:16: ANB-H-1 Headphones -
Works with:U.S. NAVY MK-84 SONOBUOY TRAINING FILM SIGNAL UNDERWATER SOUND (SUS) 81204 - 12 minutes - Sound Underwater Signal Mk 84 Mod 0. Non Explosive, can be set to one of 4 preset codes. 2.95 & 3.55 kHz: can be heard with: AN/BQR-2, AN/BQR-7, AN/UQC underwater telephone on the third harmonic (aprox. 10 kHz)
R-316A Dual receive channel sonobuoy receiver - 16 frequency channels
SSQ-15 Range only (sends out pings every 5 seconds)
SSQ-2b non-directional (Explosive type)
Coordinated Anti-Submarine Warfare - SONAR, Sonobuoys, USS Stein, USS Badger 20890 HD - 19 minutes - about fleet operations
ASW The Submariners - USS Shark, Anti-submarine Warfare Maneuvers 20800 HD - 29 minutes - @12:22: USS Holland First US sub
Hunter Killer Anti-Submarine Wwarfare U.S. Navy Film 30102 - 21 minutes - Edward R. Murrow (Wiki) - Prop planes
Blind Man's Bluff - History Channel Documentary - 1hr 35min - Some factual errors, see: SOSUS
HD Historic Stock Footage AERIAL ANTI-SUBMARINE WARFARE - @4:34 MAD chart output,
The Guide To Submarines Documentary - welldone
Inside a Navy anti-Submarine Lockheed P-3 Orion Aircraft - Moffett Field Museum -14 -
Visualizing Humpback Whale Calls using DIFAR Sonobuoy -
Modern Sonar Sounds and other Sounds of the Sea - LOFAR
Lockheed P-3 Orion Training Mission- Part 1, Part 2 -
P-3 Orion 50th Anniversary -
Project Tinkertoy (IC Precursor) 1953 US Navy; Automated Manufacturing of Modular Electronics - @4:43 shows Sonobuoy (or?) -
Submarine Communications: "Signal, Underwater Sound (SUS) Mark 84" US Navy Training Film -
The Cutting Edge ASWS-3 Viking 1980 VS-24 (23:50 training video)
Sub Killers Part 11960 Walter Cronkite S2F Tracker - USS Randolf exercise
Sub Killers Part 2 S2F -
Sippican's expendable probes - temperature, sound velocity, conductivity, etc.
Sonar Training Record Series D16: training sonobuoy audio from records
Expendable Radio Sonobuoy Training Records, 15P3: training sonobuoy audio from records
USS Pampanito Operating Equipment: sounds
Net and Boom Defenses - Ordnance Pamphlet 636A June 1944
Welcome to USS PAMPANITO (SS-383) - SS-383 Sonobuoy web pages - Manual for Expendable Radio Sono-Buoy Training (phonograph) Records -
Chapter 16 SOFAR, Harbor Defense, and other SONAR Systems - Fig 16-9 shows the above hydrophone. - JM-4 sonobuoy schematic dia -
Naval SONAR -
WiNRADiO AX-61S Sonobuoy Telemetry Antenna- 135 to 175 MHz.
Harvard Underwater Sound Laboratory. Records of the Underwater Sound Laboratory : an inventory
OEG REPORT No. 51, ANTISUBMARINE WARFARE IN WORLD WAR II, Charles M. Sternhell and Alan M. Thorndike 1946 - links to contents do NOT work
page created 22 Oct 20112