DE102013100894A1 - Underwater sound signal, Underwater transmitter or Underwater receiver, Underwater sonar, Underwater vehicle and Retrofit kit - Google Patents

Abstract

In particular in the case of a sidescan sonar, in order to be able to detect objects at great distances, great intensities are emitted in relation to the sound pressure under water, so that the reflected signal from objects far away can be easily detected. This approach has some disadvantages. To be able to reach the high sound pressure, powerful energy sources such as batteries are necessary. In addition, (interference) signals are also reflected on the water surface. Furthermore, reflections from nearby objects are very strong, so the sensitivity of underwater microphones must be reduced. The invention thus relates to an underwater sound signal which has a first transit time difference and / or a first intensity difference along a first radiation angle, the first transit time difference and / or the first intensity difference being impressed on the underwater sound signal and these impressions taking place in particular when transmitting or receiving.

Description

The invention relates to an underwater sound signal having a first time difference and or a first intensity difference along a first radiation angle and an underwater transmitter or receiver, and an underwater sonar, an underwater vehicle, a watercraft and a retrofit kit.

Particularly in the case of a sidescan sonar, in order to be able to detect objects at great distances, high intensities with respect to the sound pressure under water are emitted into a wide sector, so that the reflected signal can be well detected both from nearby and from distant objects.

This procedure has some disadvantages. In order to achieve the high sound pressure in a large sector, powerful energy sources such as batteries are necessary. In addition, (interfering) signals are also reflected on the water surface (multipath propagation). Furthermore, the echoes of nahliegender objects are very strong compared to objects in long distances, resulting in high demands on the dynamics of the receiver.

The object of the invention is to improve the disadvantages of the prior art.

The object is achieved by an underwater sound signal, which has a first time difference and / or a first intensity difference along a first radiation angle, wherein the first time difference and / or the first intensity difference is impressed on the underwater sound signal and these impressions takes place in particular when transmitting or receiving.

By emitting such underwater sound signals, the transmitters can be manufactured in smaller designs, since cooling and power supply can be dimensioned or dimensioned smaller. In addition, a lower cooling capacity is necessary. Also under the same energy supply underwater sound signals can be sent over a longer period of time than in the prior art. In particular, the transmission power can be reduced by up to 80%.

On the receiver side, the receivers can be used with high sensitivity in order to be able to detect distant objects, while at the same time measuring reflected signals from the near range with great sensitivity.

In addition, there is less volume reverberation as well as surface reverberation. Also multipath effects, which arise in particular by the additional reflection on the water surface, can be minimized.

The following concept is explained:
"Underwater sound signals", hereinafter also referred to as underwater signals, include all sound signals that are used to locate objects under water. In particular, the underwater sound signals are included, which are used in a sonar (sound navigation and ranging). Underwater ultrasound signals in the range from 10 kHz to 1000 kHz are particularly preferred. Present underwater sound signals are generated in particular by means of piezoceramics under water.

A "runtime difference" includes both a delayed and a premature emission with respect to an unaffected underwater sound signal.

An "intensity difference" is given when the intensity deviates from the intensity of a reference signal, wherein the reference signal has a substantially uniform and over a (transmission) angle φ constant intensity.

Both the intensity difference and the transit time difference can be selected via the aperture of the antenna as an angle so that they are adapted to the task. In particular, the intensity difference and transit time difference can be adapted to the angle-dependent seabed distance.

The aperture of the antenna designates the free, active aperture through which the sound waves are emitted or received.

An "emission angle" can be described in particular by a mathematical line angle, which in turn can be described by a mathematical angle measure. The line angle may alternatively be referred to as a one-dimensional angle. In radian measure, this (one-dimensional) radiation angle can assume values between 0 and 2π, in the degree measure between 0 ° and 360 ° and in the geodesic angle measure a value between 0gon and 400gon. The emission angle extends in particular along the aperture.

"Impact" includes a technical influence on the underwater sound signal, so that there is a corresponding difference in transit time and / or a difference in intensity compared to an uninfluenced signal. This can be done both during the actual transmission and when receiving. Nevertheless, cases are also included in which technically acted upon a transmitted signal after transmission and before receiving becomes. This can be done in particular by passing an already emitted signal first through water, then passing it through diffraction at layers of different thickness or different acoustic impedance before it reaches the actual receiver.

In a further embodiment, the underwater scarf signal has a second transit time difference and / or a second intensity difference along a second radiation angle, wherein the first radiation angle and the second radiation angle are not parallel to each other, so that the first radiation angle and the second radiation angle form a solid angle, wherein the second Difference in transit time and / or the second intensity difference is impressed on the underwater sound signal and this imprinting takes place in particular during transmission or reception.

Thus, an underwater sound signal can be provided which is suitable for scanning areal areas.

By "non-parallelism" or "orthogonality" of the first and second radiation angle, for example, a transmitted sound cone is included. Furthermore, the non-parallelism comprises both perpendicular line angles and other angles. It is always characteristic in this case that flat scanning is feasible.

The "solid angle" describes, in particular, the size of a spatial area that is spanned by a conical surface.

In order to be able to provide different underwater sound signals with different propagation characteristics for sonars, one of the emission angles can have a value between 0 ° and 360 °, in particular between 0 ° and 180 ° or between 0 ° and 90 ° or between 10 ° and 80 °. Even smaller angles, for example, between 20 ° and 40 ° can be realized.

The angle value of 0 ° to 360 ° can be achieved, for example, by a signal emitted by a piezoceramic ball or a piezoceramic ring. Even with small distances from each other spaced transmission elements can fill such radiation angle, it is harmless that small areas are recessed. Small distances in this context include values from 1 mm to values of a few centimeters, depending in particular on the transmission wavelength. Roughly speaking, the higher the transmission frequency, the smaller the distance can be chosen (for example, 1000 kHz equals about 1 mm spacing).

In a further embodiment, the imprinting of the transit time difference and / or the intensity difference takes place by means of a damping element and / or by means of a transmitter and / or receiver geometry and / or by means of an electronic circuit.

Thus, alternative generation methods for underwater sound signals according to the invention can be provided.

The following concept is explained:
In particular, a "damping element" comprises a material which has a different propagation velocity for the sound than water. Thus, both "delays" and "accelerations" are possible. In particular, the attenuation element in the propagation direction of the water sound can have different thicknesses, by means of which the underwater sound signal can be technically modeled.

The imprinting by means of a "transmitter and / or receiving geometry" takes place, for example, in that a plurality of individual underwater sound transmitters are not arranged flat but curved relative to one another. In particular, underwater sounders with ceramic filaments, which are arranged in a resin structure and which have a deviating from a plane structure by means of milling cutter are included.

When imposing a time difference or an intensity difference by means of an "electronic circuit", individual transmitters or individual receivers are electronically controlled in such a way that they send or receive ahead of neighboring individual transmitters or receivers premature or delayed.

Furthermore, the object is achieved by an underwater transmitter or an underwater receiver, which emits or receives a previously described underwater sound signal.

Thus, an underwater transmitter can be provided with better range, lower volume reverberation, lower surface echo, lower multipath, lower transmit power, lower cooling, lower power consumption, and smaller form factor.

Furthermore, the object can be achieved by an underwater transmitter or an underwater receiver, wherein the underwater transmitter or the underwater receiver is set up such that the underwater transmitter or the underwater receiver active and / or passive an underwater sound signal Difference in transit time and / or a first intensity difference along a first radiation angle and / or that the underwater transmitter or underwater receiver actively and / or passively impress a second time difference or a second intensity difference along a second radiation angle to the underwater sound signal.

This underwater transmitter or underwater receiver also has the advantages of the previously described underwater transmitter or underwater receiver.

In one embodiment, the underwater transmitter has two or more subsenders and / or the underwater receiver has two or more sub-receivers.

As a result, a transit time difference or an intensity difference can be impressed on an underwater sound signal in a particularly effective manner. It is particularly advantageous that any desired time differences and intensity differences can be realized. Thus, for example, the intensity and / or transit time can be impressed on the transmitter or receiver as a function of a distance of a seabed to be examined.

In this case, the subsenders comprise both (piezo) ceramic filaments and also flat (piezo) ceramic elements or (piezoceramic) ceramic elements arranged on a curved path.

In order to be able to emit underwater sound signals according to the invention, in particular with existing sonars, the active impingement can take place electronically. In particular, individual subscribers or sub-receivers can prematurely and / or late send or receive a sound signal.

The big advantage in this case is in particular that an adaptation of the existing sonar to a system according to the invention can be easily implemented by a software update.

In another embodiment, the passive imposition is effected by a geometric arrangement of the underwater transmitter and / or by a geometric arrangement of the underwater receiver and / or by a damping element.

With regard to the realizations and definitions of the geometric arrangement and the damping element is made to previous versions, which apply analogously.

In a further embodiment, the object is achieved by an underwater sonar, which has a previously described underwater transmitter and / or a previously described underwater receiver.

Thus, powerful locators for detecting underwater objects can be provided.

Furthermore, the object is achieved by an underwater vehicle having a previously described underwater transmitter and / or a previously described underwater receiver and / or a previously described underwater sonar.

The "underwater vehicle" includes both submarines (remote-controlled, autonomous, with and without crew) as well as buoys, torpedoes, or towing sonars.

In a further embodiment of the invention, the object is achieved by a watercraft, which has a previously described underwater transmitter and / or a previously described underwater receiver and / or a previously described underwater sonar and / or a previously described underwater vehicle.

"Watercraft" in the present sense includes all ships, platforms or other moving or lingering objects on the water.

Finally, the object can be achieved by a retrofit kit for retrofitting a sonar, wherein the retrofit kit a sonar transmitted or received underwater sound signal a first time difference and / or a first intensity difference along a first radiation angle and / or that the underwater transmitter or underwater receiver the underwater sound signal a second delay difference and / or impresses a second intensity difference along a second radiation angle, wherein said impacting occurs in particular during transmission or reception.

Thus, a component or software update can be provided which sets in-use sonars such that these sonars send or receive a previously described underwater sound signal. This leads to high efficiency increases of existing sonar systems at low cost.

In a related embodiment, the retrofit kit is passive and / or active. Thus, alternative retrofit kits can be provided.

For the definition of the terms "passive" and "active", reference is made to the previous statements.

Furthermore, the invention will be explained in more detail with reference to embodiments. Show it

1 a highly schematic representation of an underwater sounder with ceramic filaments,

2 a highly schematic representation of a conventional, flat underwater sounder,

3 a highly schematic representation of a curved underwater sound transmitter with several sub-underwater sounders,

4 a schematic representation of a side scan sonar with abscannbarer surface,

5 a graphical representation of an intensity profile as a function of the distance and

6 a schematic representation of a submarine side scan sonar.

In a first alternative of the underwater sounder 101 , shows a first underwater sounder 101 a variety of ceramic filaments 105 on which on a carrier layer 103 are arranged. The ceramic filaments 105 consist of piezoceramics, which controlled by a voltage perform a change in space, whereby a water column, an underwater sound signal is impressed.

In a simple manufacturing process for the present underwater sounder 101 become the ceramic filaments 105 arranged side by side and filled by means of a resin. Subsequently, the ceramic block is cured and then with enclosed ceramic filaments 105 machined by means of a milling cutter. By the cutter, a defined surface, such as a curved surface, the ceramic block is impressed.

Present first underwater sounder 101 is used differently. First, all ceramic filaments 105 simultaneously charged with voltage. Due to the different position of the ceramic filaments 105 An underwater sound signal corresponding to the surface course is emitted.

Another alternative is to individually connect each individual ceramic filament. By corresponding earlier or later wiring, a desired signal shape with a corresponding desired signal intensity and / or with an angle-dependent transit time and / or intensity difference can be provided.

In a second alternative is a second underwater sounder 201 with flat, flat ceramic plates 205 designed. The ceramic plates 205 are spaced apart from each other (not shown).

Because of the ceramic plates 205 from inside (φ = 0) to outside (φ = φ _max ) are connected, there is a difference in transit time as a function of the angle φ, which is a curved sound waveform 207 sending out. By a different timing of the wiring different underwater sound waveforms can be emitted. Alternatively or in addition, the individual ceramic plates 205 connected so that different intensities are emitted in different directions.

In a third alternative has a third underwater sounder 301 curved - on a support structure 303 arranged - piezoceramics 305 on.

Due to the geometric arrangement (curvature) is at simultaneous activations of the piezoceramics 305 the underwater sound signal imprinted a transit time difference. Alternatively or additionally, the individual piezoceramics 305 connected so that different intensities are emitted in different directions.

As in the previous examples, a time difference and / or an intensity difference can be impressed on an underwater sound signal by time-delayed activation or by different activation.

Each of the alternative underwater sounders described above 101 . 201 . 301 can be used in a side scan sonar. In this side scan sonar 411 will be left 415 and right 413 scanned the seabed.

To minimize or avoid mutual interference, point the scanned surfaces 413 . 415 a distance 421 on, with the left surface 415 a width 418 and the right surface 413 a width 417 having. Overall, the seabed can cover a total width 423 and over a covered distance 419 be scanned.

By doing the sidescan sonar 411 moving under water can create a complete "picture" of the sea surface and any objects on it 641 . 643 be determined.

A sidescan sonar 611 with one of the previous underwater sounders 101 . 201 . 301 is below a water surface 650 and above the seabed. The distance 652 to the sea bottom is 10m, this can be less in shallow water and more in deep water.

Basically, the wiring is as follows.

It will be the underwater sounder 101 . 201 . 301 connected in such a way that the sound signal in the direction of the maximum range R _max to be scanned 663 with maximum intensity (φ = 0). As the angle φ increases further signals are transmitted, each with attenuating intensity, and finally the emission with the minimum intensity takes place with a minimum range R _min to be scanned 661 (φ = φ _max ).

By adjusting (depending on the height 652 ) the underwater sounder 101 . 201 . 301 the emitted signals are modeled such that substantially similar intensities of intensity of the reflected sound signals on the sidescan sonar 611 be received.

This allows objects in particular 641 . 643 , which are located at different distances to the side scan sonar are detected similarly good.

A typical intensity curve as a function of the detection direction is in 5 shown. The area 531 corresponds to the surface and the area 533 is the course of the underwater signal.

LIST OF REFERENCE NUMBERS

101

first underwater sounder

103

backing

105

Keramikfilament

201

second underwater sounder

203

backing

205

planar piezo elements

207

signal front

301

third underwater sounder

303

backing

305

curved piezo element

411

Side scan sonar

413

right scanning surface

415

left scan area

417

Scan width R

418

Scan width R

419

scan width

421

scan gap

423

scan expansion

531

surface

533

Underwater signal

611

Side scan sonar

641

first object

643

second item

650

water surface

652

vertical ground clearance

661

first sound control limit

662

second sound control limit

Claims (14)

Underwater sound signal 207 which has a first transit time difference and / or a first intensity difference along a first emission angle (φ), characterized in that the first transit time difference and / or the first intensity difference is impressed on the underwater sound signal and this imprinting takes place in particular during a transmission or reception. Underwater sound signal according to claim 1, characterized in that the underwater sound signal has a second transit time difference and / or a second intensity difference along a second radiation angle, wherein the first angle and the second angle are not parallel to each other, so that the first line angle and the second line angle form a solid angle , Wherein the second transit time difference and / or the second intensity difference is impressed on the underwater sound signal and this imprinting takes place in particular during the transmission or the reception. Underwater sound signal according to one of the preceding claims, characterized in that one of the emission angle has an angle value between 0 ° and 360 °, in particular between 0 ° and 180 ° or between 0 ° and 90 ° or between 10 ° and 80 °. Underwater sound signal according to one of the preceding claims, characterized in that the imprinting of the transit time difference and / or the imprinting of the intensity difference by means of a damping element and / or by means of a transmitter and / or receiving geometry and / or by means of an electronic circuit. An underwater transmitter or receiver which transmits or receives an underwater sound signal according to any one of the preceding claims. Underwater transmitter or receiver, characterized in that the underwater transmitter or receiver is arranged such that the underwater transmitter or receiver an underwater signal active and / or passive a first time difference and / or a first intensity difference along a first radiation angle and / or that the underwater transmitter or receiver actively and / or passively impress a second transit time difference and / or a second intensity difference along a second radiation angle to the underwater signal. Underwater transmitter ( 101 . 201 . 301 ) or receiver according to claim 6, characterized in that the underwater transmitter has two or more subsenders ( 105 . 205 . 305 ) and / or the underwater receiver has two or more sub-receivers. Underwater transmitter or receiver according to one of claims 6 or 7, characterized in that the active impingement is carried out electronically. Underwater transmitter or receiver according to one of claims 6 to 8, characterized in that the passive impingement is effected by a geometric arrangement of the underwater transmitter and / or by a geometric arrangement of the underwater receiver and / or by a damping element. Underwater sonar comprising an underwater transmitter and / or an underwater receiver according to any one of claims 5 to 9. Underwater vehicle ( 441 . 611 ) comprising an underwater transmitter and / or an underwater receiver according to any one of claims 5 to 9 and / or underwater sonar according to claim 10. A watercraft comprising an underwater transmitter and / or an underwater receiver according to any one of claims 5 to 9 and / or underwater sonar according to claim 10 and / or an underwater vehicle according to claim 11. Retrofit kit for retrofitting a sonar, wherein the retrofit kit a sonar transmitted or received underwater sound signal a first time difference and / or a first intensity difference along a first radiation angle and / or that the underwater transmitter or receiver the submarine signal a second transit time difference and / or a second intensity difference along impressed on a second radiation angle, wherein this impressing takes place in particular during a transmission or a reception. Retrofit kit according to claim 13, characterized in that the retrofit kit is designed passive and / or active.

Images