High resolution, multi-beam, 600Khz side scan sonar

Along track resolution: 6.2cm@50m, 15.5cm@125m

Across track resolution: 3.125cm

Dynamic aperture, dynamic focus and beam steering technology

Transducers and data acquisition architecture support Klein’s advanced digital signal processing algorithms.

750 m depth rating.

Optional Swath Bathymetry and Gap filler

Specifically designed to obtain SAS quality pictures while operating in difficult sea conditions

High speed (14kts) route survey & mine classification.

Klein’s flagship 5900 high-resolution and high-speed side scan sonar is designed for use as either a conventional towed system or a pay-load for an unmanned surface vehicle (USV). We recently tested our newest sonar features in Israel on the USV Seagull, Elbit’s versatile plat-form for mine hunting and anti-submarine war-fare. Among these features is the ability to con-trol and stream full-resolution sidescan sonar images via satellite. During a recent test, the Klein 5900 made several passages over the wreck of the Italian Submarine Scirè, sunk by the British naval trawler Islay in1942. The Scirè lies in 35 meters of water on a sandy bottom, six miles outside of Haifa. In 1984 the Italian Navy Special Forces “COMSUBIN” led a successful mission with the ship Anteo to re-trieve the remains of 42 bodies trapped inside. The operation that led to the sinking of Scirè is interesting. It was made possible by the lead-ing-edge technology then used by the British intelligence service. The Scirè, avidly sought by the Allies after its string of successful missions, left the docks of the Italian Navy base in Taranto on July 29, 1942 on a mission to attack the then-British port of Haifa. The details of the mission had been communicated by the Italians to their German allies, neither aware that the German state-of-the-art encrypted communication sys-

tem Enigma had recently been compromised by the British intelligence service using Alan Turing’s newly developed machine, precursor to today’s computers (see the Oscar winning movie The Imitation Game). The decoding of the ciphered communications between Italy and Germany meant the fate of the Scirè was sealed from the

moment she left the docks. The submarine was allowed to enter unchallenged into Haifa Bay and was then trapped from the outside by the British forces. The Islay hit the Scirè with depth charges in the late afternoon of August 10. The submarine was forced to surface and to strike back, but once on the surface, was pounded by land artillery and sunk. Further depth charges completed its de-struction and sealed the fate of all crew members.

Wreck of the WWII Italian submarine Scirè Haifa, Israel (1938—1942)

Klein System 5900 at a glance

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Volume 2, Issue 1

July 2017

The Surveyor Notebook

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Volume 2, Issue 1

July 2017 In this image the 5900 is

flying from SW to NE

passing the wreck of the

Scirè to its left. The

sound waves are cap-

tured by the portside

transducer.

(1) A shadow with no

attached bright reflec-

tion indicates an object

in the water column, in

this case possibly a

buoy or fish net (2).

The sail and the mast of

the Scirè stand out

clearly, both in the tar-

get and in the shadow

with exceptional sharp-

ness. (3) The surveyor

knows a basic yet im-

portant rule. Along the

direction of sound (in

this case the wreck is

insonified bottom-right

to top-left) a shadow

followed by bright indi-

cates a depression, in

the bottom. (4) Bright

followed by shadows

indicates a feature rais-

ing from the bottom. In

this case clearly the hull

of the submarine.

Pipeline

Horse

Ferry

Historical

Marker Sign

Klein commercialized the dynamic focus with the 5000V2. In the Klein 5900, there are 28 independent receive sub-

arrays on each side. Each sound sample from each element is recorded and stored in memory. A software process

subsequently takes into account position information, motion sensor and user’s parameters, to retrieve the

appropriate sound samples from the sound memory to compose a synthetic image. By the laws of

physics, sonar waves reflected from a target have different radiuses depending on the distance of

the target. When the operator focuses on 25 meters, the 5900 software delays each sound

sample to adapt to the corresponding radius. At 75 meters the radius is larger etc. The

focusing, i.e. computing the delay of each sound sample, is one of the reasons

behind the 5900 crisp imagery. Beam steering is a technique made possible

by the 5900 sound processing architecture. Motion sensor information

(heading, pitch, roll and yaw) feed into the 5900 algorithms to

compose synthetic beams pointing orthogonally to the course

over ground, as opposed to orthogonally to the towfish

heading which is more subject to inevitable

fluctuations. This is why the 5900, unique in its

class, is designed to operate and to produce

crisp clear imagery even in high sea states

or in shallow waters where sea waves

have a grater effect on the towing

vessel.

Zebra

Mussels

2

2

What is dynamic focus and beam steering ?

1

3

3

4

Shorter range Longer range

All sonar images are acquired with Klein S5900 side scan sonar, operated with a K-Wing III depressor, through the A-frame of the Elbit Seagull USV. Recorded on radio link at the

Elbit Headquarter via SonarPro® V14.0 Survey and Targeting Software via Klein proprietary SP-Link. Post processing in Chesapeake Sonarwiz® .

http://www.marina.difesa.it/storiacultura/storia/palazzomarina/Pagine/IlsommergibileScireaspx

http://www.marina.difesa.it/storiacultura/storia/medaglie/Pagine/scire.aspx