DE102018222487A1 - Arrangement and method for locating an object in or under a body of water - Google Patents

Abstract

The present invention relates to an arrangement and a method which are able to locate an object in or under a body of water. An underwater drive vehicle (1) with a drive (6, 8, 9) and a direction change unit (4.1, 4.2, 23.1, 23.2) moves the arrangement through the water. An underwater measuring body (2) is connected to the underwater drive vehicle (1) by a connecting element (3). The underwater measuring body (2) comprises a first magnetometer (12.1) and a second magnetometer (12.2, ...). Each magnetometer (12.1, 12.2, ...) measures a quantity that correlates with the magnetic field around this magnetometer. A data storage unit (21, 22) automatically stores signals from the two magnetometers (12.1, 12.2, ...).

Description

The invention relates to an arrangement and a method which are able to locate an object in or under a body of water. For example, sea mines, aerial bombs and other weapons should be located so that they can then be neutralized. Such an object can often not be located with sufficient accuracy using optical methods.

The arrangement and the method take advantage of the fact that an object to be localized creates an anomaly in the earth's magnetic field which can be discovered.

A possible embodiment for such an arrangement is that a surface ship tows a measuring body through the water. A magnetometer is installed on board this measuring body. An evaluation unit evaluates the signals from this magnetometer.

Another possible embodiment is an underwater vehicle with its own drive, which has a magnetometer and an evaluation unit for the signals from the magnetometer.

The invention has for its object to provide an arrangement and a method for localizing an object in or under a body of water, which are able to localize this object with greater certainty than known arrangements and methods.

This object is achieved by an arrangement with the features specified in claim 1 and a method with the features specified in claim 17. Advantageous further developments result from the subclaims, the following description and the drawings.

The arrangement according to the invention and the method according to the invention are designed to localize an object, this object being located in or under a body of water, in particular completely or at least partially below the surface of the bottom of this body of water. The arrangement according to the invention is designed to be used completely below the surface of the water.

• - ein Unterwasser-Antriebsfahrzeug,
• - einen Unterwasser-Messkörper, der während des Einsatzes der Anordnung in einem Abstand zum Unterwasser-Antriebsfahrzeug angeordnet ist,
• - ein Verbindungselement, welches das Unterwasser-Antriebsfahrzeug mit dem Unterwasser-Messkörper verbindet, und
• - eine Datenspeicher-Einheit.

The arrangement according to the solution comprises

• - an underwater propulsion vehicle,
• an underwater measuring body which is arranged at a distance from the underwater drive vehicle during use of the arrangement,
• - A connecting element which connects the underwater drive vehicle with the underwater measuring body, and
• - a data storage unit.

• - einen Antrieb und
• - eine Fahrtrichtungs-Änderungs-Einheit.

The underwater propulsion vehicle includes

• - a drive and
• - a direction change unit.

• - ein erstes Magnetometer und
• - mindestens ein zweites Magnetometer.

The underwater measuring body includes

• - a first magnetometer and
• - At least a second magnetometer.

Each magnetometer of the underwater measuring body can measure a size, which size correlates with the magnetic field around this magnetometer. The data storage unit can automatically store signals from the two magnetometers.

• - Die Anordnung wird unter Wasser durch das Wasser bewegt.
• - Jedes Magnetometer misst eine Größe, die mit dem Magnetfeld um dieses Magnetometer korreliert.
• - Die Datenspeicher-Einheit speichert automatisch Signale von den beiden Magnetometern ab.

The method according to the solution comprises the following steps:

• - The arrangement is moved under water through the water.
• - Each magnetometer measures a quantity that correlates with the magnetic field around this magnetometer.
• - The data storage unit automatically stores signals from the two magnetometers.

According to the solution, the underwater drive vehicle moves the entire arrangement through the water with the drive. This makes it possible to design the underwater measuring body without its own drive. Such a drive on board the underwater measuring body could falsify the measurements of the magnetometers on board the underwater measuring body. The connecting element between the underwater drive vehicle and the underwater measurement body can be designed so long that the distance between the underwater drive vehicle and the underwater measurement body is sufficiently large and the drive of the underwater drive vehicle does not significantly falsify the measurements of the magnetometers .

In addition, the drive-free underwater measuring body can be designed more simply than an underwater measuring body with its own drive. The underwater measuring element consumes only a little electrical energy during operation, usually only the energy required to operate the magnetometer and optional additional sensors. This energy can often be supplied via the connecting element, so that no voltage source is required on board the underwater measuring body.

According to the solution, the underwater propulsion vehicle comprises a direction change unit, e.g. a rudder and / or an elevator, and can change the direction of travel and / or the depth of the arrangement through the water. This makes it possible to design the underwater measuring body without a movable change of travel unit and without an actuator for such a unit. Such an actuator could also falsify the measurement results from the magnetometers and requires energy.

The following advantage occurs especially when objects are to be located that are at least partially below the surface of the water floor and thus completely or at least partially below the water. The underwater measuring body should generally be moved close to the bottom of the water in order to be as close as possible to an object on or below the surface of the bottom of the water. The arrangement according to the solution is moved by the underwater propulsion vehicle through the water and can remain completely below the water surface during use. This avoids the need for a surface vehicle to move the underwater measuring body through the water. If a surface vehicle were to be used, there would inevitably be a greater vertical distance between the surface vehicle and the underwater measuring body, this distance depending on the water depth and thus generally varying during the journey. The connection must be long enough, often four times the depth of the water, so that the mechanical connection between the surface-mounted vehicle and the underwater measuring body is sufficiently well managed. The use of an underwater vehicle as a propulsion vehicle in accordance with the solution avoids the need to provide such a long mechanical connection. In addition, thanks to the invention, wave movements and wind have no influence on the arrangement according to the solution, because in use it remains permanently below the water surface.

The invention takes advantage of the fact that an object to be localized often causes an anomaly in the earth's magnetic field. A magnetic field anomaly is understood to mean a local deviation of the actual magnetic field, for example measured as magnetic flux density in nano-Tesla, from a normal magnetic field. The normal magnetic field is the earth's magnetic field, which is mainly caused by the earth's core and also by the ionosphere and the magnetosphere and is approximately an eccentric dipole field with a 12 degree inclination to the earth's axis. The local deviation caused is, for example, a deviation in the direction and / or the intensity of the magnetic field.

According to the solution, the underwater measuring body comprises several magnetometers. A magnetometer can be designed as a passive sensor. A magnetometer does not necessarily actively create a physical effect. This means that little electrical energy is required on board the underwater measuring body. In addition, the underwater measuring body is more difficult to discover during use than when the underwater measuring body produces a physical effect. The physical effect can have undesirable effects, especially on living creatures in the water, or cause a weapon to explode. In addition, especially in military applications, it is often not desired that the underwater measuring body be discovered. This risk is less with a purely passive sensor.

According to the solution, the underwater measuring body comprises at least two magnetometers, between which a distance inevitably occurs. Because of this feature, the arrangement can detect and locate an object in or under the water with greater certainty than if only a single magnetometer were present. One reason for this: An object to be localized often causes an anomaly in the magnetic field around the magnetometer. This anomaly warps the magnetic field lines near the object. However, the anomaly caused is several orders of magnitude smaller than the earth's magnetic field, for example a few percent of the magnetic flux density of the earth's magnetic field, so that a single magnetometer alone cannot often detect the anomaly with sufficient certainty. The magnitude of the anomaly also decreases sharply as the distance between the object and the magnetometer increases.

The feature that at least two magnetometers are present makes it possible to calculate differences between the measurement results of these two magnetometers spaced apart from one another. If the magnetic field has no anomaly in the vicinity of the underwater measuring body, the measurement results of the two magnetometers ideally do not differ from one another, so the difference is ideally zero. In reality there are differences due to the measurement inaccuracies of the magnetometer, but these are below a predetermined tolerance if there is no anomaly. An anomaly, on the other hand, leads to a difference in the measurement results that lies above the specified tolerance. Because the underwater measuring body has at least two magnetometers includes, the likelihood is greater that an anomaly can be detected by a significantly higher difference - compared to an underwater measuring body that has only a single magnetometer.

One degree of freedom in the design of the underwater measuring body is the distance between the two magnetometers. The smaller the distance, the greater the probability that an object causes an anomaly in the two magnetic fields around the two magnetometers and therefore both magnetometers discover the object and localize it together. By evaluating the signals from these two magnetometers, it is often possible to automatically derive a characteristic of the object and / or the position of the object relative to the surface of the water floor. On the other hand, the smaller the distance between the magnetometers, the smaller the streak on the surface of the body of water that the underwater measuring body examines while traveling. With a smaller distance, the examination of an area of the surface of the water floor therefore often takes longer, but the objects to be discovered are actually discovered and localized with greater certainty.

In one configuration, the arrangement further comprises an evaluation unit. The evaluation unit can automatically evaluate the signals which the magnetometers have generated and which the data storage unit has stored. The evaluation unit can be on board the underwater propulsion vehicle, on board the underwater measuring body or on board a spatially distant platform, e.g. a surface vehicle, another underwater vehicle or a land station. If the evaluation unit is arranged on board the platform, the underwater drive vehicle does not need to move the evaluation unit through the water and to supply it with electrical energy during the journey.

In one embodiment, the evaluation unit can automatically detect a difference between the signals from the two or at least two magnetometers of the underwater measuring body and evaluate this difference. Because of this feature, the arrangement can detect and locate an object beneath the surface of the body of water with greater certainty than if only a single magnetometer were present or if signals from several magnetometers were evaluated independently of one another. Although the anomaly that an object creates is several orders of magnitude smaller than the Earth's normal magnetic field, an object near the underwater measuring body often results in two different anomalies in the magnetic fields around the two magnetometers, so one difference causes that the evaluation unit is able to discover and evaluate. Thus, this feature increases the likelihood that an object will actually be discovered and located.

As already mentioned, a degree of freedom in the design of the underwater measuring body is the distance between the two magnetometers. At a small distance, an object creates an anomaly in each of the two magnetic fields, the anomalies often differing from one another.

In a preferred embodiment, each magnetometer is designed as a multi-axis magnetometer, ie as a vector sensor. The multi-axis magnetometer can in particular be designed as a three-axis magnetometer or a four-axis magnetometer. If the magnetometer can measure in more than three different directions, redundancy is achieved and noise in the signals can be better eliminated. A four-axis magnetometer, for example, can be implemented as a pair with two two-axis magnetometers.

Each magnetometer designed as a vector sensor can detect the direction from itself to a source for an anomaly in the magnetic field. This anomaly often originates from an object to be discovered, which thus becomes an interfering element in the earth's magnetic field. Overall, the underwater measuring body measures at least two multi-axis magnetometers, i.e. at least two directions to an object. Knowledge of these two directions is often sufficient to determine the position of the object relative to the underwater measuring body and the distance and position of the object relative to the surface of the water floor.

According to this embodiment, the two magnetometers each calculate a gradient, that is to say a vector, and thus act together as a gradiometer.

The distance between the two magnetometers and the length of the connecting element are known. The underwater propulsion vehicle is often able to measure its own geoposition. From the directions that the multi-axis magnetometers have discovered, the geoposition of the underwater propulsion vehicle at the time of the measurement and the known dimensions, the geoposition of the object in or under the water can often be derived at least approximately.

According to the solution, the underwater measuring body comprises a first magnetometer and a second magnetometer. In one embodiment comprises the underwater measuring body is a third magnetometer. This third magnetometer is arranged with a distance between the first two magnetometers.

The use of a third magnetometer on board the underwater measuring body increases the measuring accuracy and provides redundancy.

If the underwater measuring body only has two magnetometers and these are not designed as vector sensors, the situation can arise that an object in or under the water always causes the same anomaly in the two magnetic fields around the two magnetometers, for example because of the Object always has the same distance to the two magnetometers, while the arrangement is moved past the object. In this case, an evaluation unit would not find any difference in the signals from the two magnetometers and therefore may not be able to detect or locate the object. The configuration with the third magnetometer also prevents this undesirable situation from occurring when the three magnetometers are not vector sensors.

It is possible that the third magnetometer is also designed as a multi-axis magnetometer. Thanks to this configuration, three directions to an object can be measured. This configuration further reduces the risk of a measurement error. The direction to an object and - in the case of an object under the water - the position of the object relative to the surface of the water floor can be determined with greater certainty. The configuration with the third magnetometer also provides redundancy: if one magnetometer fails, two magnetometers are still available.

• - einen Unterschied zwischen den Signalen des dritten Magnetometers und den Signalen des ersten Magnetometers,
• - einen Unterschied zwischen den Signalen des dritten Magnetometers und den Signalen des zweiten Magnetometers.

An optional evaluation unit can discover at least one of the following differences in a further development of this embodiment:

• a difference between the signals of the third magnetometer and the signals of the first magnetometer,
• a difference between the signals of the third magnetometer and the signals of the second magnetometer.

This configuration further increases the likelihood that an object will be discovered because the object leads to an anomaly in a magnetic field around a magnetometer. This probability is greater if three magnetometers are used instead of just two.

In a preferred embodiment, the underwater measuring body comprises a fourth magnetometer. When the underwater measuring body is used regularly, this fourth magnetometer is closer to the water floor than the first magnetometer and the second magnetometer.

This configuration further reduces the risk of measurement errors, in particular if the fourth magnetometer is also designed as a multi-axis magnetometer.

Preferably, the two or all magnetometers repeatedly measure the respective current magnetic field, e.g. with a given sampling rate. This creates a better picture of the surroundings of the underwater measuring body than just a measurement at a single point in time.

In a preferred embodiment, the underwater measuring body comprises at least one distance sensor. This distance sensor can measure the distance between itself and thus the underwater measuring body and the water bottom. The underwater measuring body is able to transmit signals from the distance sensor to the underwater drive vehicle. The underwater drive vehicle is designed to move the arrangement through the water as a function of signals from the distance sensor and, in particular, to control the direction change unit as a function of these signals.

In one embodiment, the underwater drive vehicle uses signals from the distance sensor on board the underwater measuring body to move the arrangement through the water. The distance sensor enables the underwater measuring body to be moved through the water near the bottom of the body of water, even when the bottom of the body of water is mountainous. In particular, it is made possible for the vertical distance between the underwater measuring body and the body of water to remain within a predetermined barrier without the underwater measuring body colliding with the body of water.

If only a distance sensor were used on board the underwater propulsion vehicle to control the arrangement through the water, the risk is greater that the underwater measuring body is at a different distance from the bottom of the water than the underwater propulsion vehicle and therefore the specified barrier is not observed or the underwater measuring body collides with the water bottom, although the underwater drive vehicle maintains the correct distance.

In one embodiment, the underwater measuring body comprises a position sensor. This position sensor is able to measure the position (orientation) of the underwater measuring body in the water, in particular while the underwater measuring body is moved through the water, for example the orientation of the underwater measuring body relative to the surface of the water bottom. The position sensor can be implemented with the aid of several distance sensors. Data about the measured position are preferably transmitted together with signals from the magnetometers to the underwater drive vehicle and stored by the data storage unit. While an optional evaluation unit evaluates the signals from the magnetometers of the underwater measuring body, a control unit of the underwater drive vehicle and / or the evaluation unit uses evaluated signals from the position sensor. The control unit can use the signals from the position sensor to control the arrangement through the water. The evaluation unit can automatically take into account the measured position (orientation) of the underwater measuring body in the water.

The evaluation unit can use the signals from the position sensor to better locate an object under the water. The direction from the underwater measuring body to the object can depend on the position of the underwater measuring body in the water.

It is possible that the data storage unit is arranged on board the underwater measuring body. In a preferred embodiment, however, the data storage unit is arranged on board the underwater propulsion vehicle. The underwater measuring body is able to transmit signals from the magnetometers of the underwater measuring body to the underwater drive vehicle. These signals are then transmitted to the data storage unit and stored by it.

This configuration further reduces the risk that the data storage unit generates a magnetic field which falsifies the measured values from the magnetometers. Rather, it is possible to maintain a sufficiently large distance between the data storage unit and the magnetometers.

• - einem Rumpf,
• - einen ersten Abstandhalter und
• - einen zweiten Abstandhalter.

It is possible that both magnetometers are mounted directly on the hull of the underwater measuring body. In another embodiment, the underwater measuring body comprises

• - a hull,
• - a first spacer and
• - a second spacer.

According to this other embodiment, the two spacers are attached to the fuselage, so that the fuselage is between the two spacers. The first magnetometer is attached to the first spacer. The second magnetometer is attached to the second spacer, in one embodiment in each case at the free outer end of the spacer.

This configuration makes it possible, on the one hand, to achieve a sufficiently large distance between the two magnetometers in a direction perpendicular to the direction of travel of the arrangement. On the other hand, the underwater measuring body according to this embodiment has a lower weight than when using a different geometric shape.

In one embodiment, the two spacers are designed as wings. These wings can be mounted on the fuselage in such a way that they achieve buoyancy when the underwater propulsion vehicle moves the underwater measuring body through the water.

In one embodiment, the arrangement comprises a motion sensor. This motion sensor is able to measure a movement of the underwater measuring body relative to the underwater drive vehicle. For example, a first 3D acceleration sensor is mounted on board the underwater drive vehicle and a second 3D acceleration sensor is mounted on board the underwater measuring body. A movement of the underwater measuring body relative to the underwater drive vehicle is automatically derived from a difference between the accelerations in one direction, which these two acceleration sensors measure.

This configuration makes it easier to ensure that the distance between the underwater measuring body and the water bottom remains in a predetermined range. A control unit on board the underwater drive vehicle receives signals from the motion sensor and controls the direction change unit and / or the drive in such a way that the distance remains in the predetermined range.

If a geoposition sensor on board the underwater propulsion vehicle is able to measure its geoposition, it is easier to determine the geoposition of an object in or under the water with the aid of signals from the magnetometers and signals from the motion sensor.

In one embodiment, the two magnetometers are attached to a hull of the underwater measuring body in such a way that their distance remains unchanged from one another, in particular during use and during transport of the underwater measuring body to a place of use. In another embodiment, the distance between the two magnetometers can be changed, for example manually before use. In this embodiment too, the distance between the two magnetometers preferably remains constant during use. By changing the distance between the two magnetometers, the underwater measuring body can be adapted to a desired application.

• - das oder ein Material, aus dem der Gegenstand oder ein Bestandteil des Gegenstands hergestellt ist,
• - die Größe oder maximale Abmessung des Gegenstands,
• - die geometrische Form des Gegenstands.

An optional evaluation unit evaluates the signals from the magnetometers and, in one embodiment, determines at least one property of the localized object through the evaluation. This configuration can preferably be combined with the configuration that each magnetometer is designed as a multi-axis magnetometer. For example, the evaluation unit determined at least one of the following properties of the object:

• - the or a material from which the object or a component of the object is made,
• - the size or maximum dimension of the object,
• - the geometric shape of the object.

When viewed in the direction of travel of the arrangement, the underwater measuring body is preferably located behind the underwater drive vehicle. In this embodiment, the underwater drive vehicle is able to control the arrangement more easily than if the underwater measuring body were located in front of the underwater drive vehicle or vertically or obliquely next to the underwater drive vehicle.

The underwater measuring body is preferably supplied with electrical energy via the connecting element. As a result, there is no need to have a voltage source on board the underwater measuring body.

In one embodiment, a buoyancy body ensures that the weight of the underwater measuring body is approximately equal to the buoyancy that the water displaced by the underwater measuring body exerts on the underwater measuring body (buoyancy neutrality). This configuration makes it easier to move the underwater measuring body through the water at a desired distance from the water bottom.

In one configuration, the arrangement comprises a further underwater measuring body, which is connected to the underwater drive vehicle via a further connecting means. The two underwater measuring bodies are preferably arranged next to one another, as seen in the direction of travel of the arrangement. With this configuration, a larger strip of the surface of the body of water can be examined than if the arrangement had only a single underwater measuring body. This saves time. For example, both underwater measuring bodies are attached to a drawbar, which pulls the underwater drive vehicle behind them.

In one embodiment, the underwater drive vehicle with the data storage unit is removed from the water after the journey. The data storage unit is read out and the stored signals are transmitted to an evaluation unit on board a platform that was spatially distant from the underwater drive vehicle during use. The evaluation unit automatically evaluates the transmitted signals.

• 1 in einer Seitenansicht die lösungsgemäße Anordnung sowie ein Schiff mit einer Auswerteeinheit;
• 2 in einer Draufsicht den lösungsgemäßen Unterwasser-Messkörper;
• 3 in einer Vordersicht den lösungsgemäßen Unterwasser-Messkörper.

The arrangement according to the invention is explained in more detail below on the basis of an exemplary embodiment shown in the drawings. Here show:

• 1 a side view of the arrangement according to the solution and a ship with an evaluation unit;
• 2nd in a plan view the underwater measuring body according to the solution;
• 3rd the underwater measuring body according to the solution in a front view.

The arrangement according to the solution of the exemplary embodiment travels through the water in a predetermined area, for example along a predetermined serpentine or meandering path, and in the process searches for the surface Mb of the sea floor. The arrangement is intended to discover and locate every object on the surface Mb of the seabed or has sunk completely or at least partially or has buried itself in the seabed. The object to be discovered triggers an anomaly in the earth's magnetic field. This anomaly can amplify the earth's magnetic field, for example if the object is a metallic object or contains metallic components. Examples of such metallic objects on or under the seabed surface Mb are mines, pipelines, refrigerators or objects made of wood, because wood under water can become metallic. An anomaly can also weaken the magnetic field, for example if the object is made of salt or lime.

The arrangement should at least approximate each geoposition discovering object and its position relative to the seabed surface Mb determine and save in a data storage. After use, the arrangement is fetched on board a platform, for example a surface ship, and the data memory is read out and evaluated. It is also possible for information about a discovered object to be transmitted to a platform even during use. A discovered suspicious item is then examined in more detail.

• - ein Unterwasser-Antriebsfahrzeug 1,
• - einen Unterwasser-Messkörper 2 und
• - ein Verbindungselement 3, welches den Unterwasser-Messkörper 2 mit dem Unterwasser-Antriebsfahrzeug 1 verbindet.

In 1 are the water surface WHERE who have favourited Seabed Surface Mb as well as an object G seen under the seabed Mb surface. In addition, in 1 an exemplary embodiment of the arrangement according to the solution is shown in a side view. The arrangement according to the solution comprises

• - an underwater propulsion vehicle 1 ,
• - an underwater measuring body 2nd and
• - a connecting element 3rd which the underwater measuring body 2nd with the underwater drive vehicle 1 connects.

It also becomes a distant ship S with a data processing evaluation unit 28 shown, which is described below.

• - eine Fahrzeughülle 7,
• - ein oberes Seitenruder 4.1 und ein unteres Seitenruder 4.2, welche an der Fahrzeughülle 7 befestigt sind,
• - ein linkes Höhenruder 23.1 und ein rechtes Höhenruder 23.2, welche ebenfalls an der Fahrzeughülle 7 befestigt sind,
• - einen Abstands-Sensor 5, der an der Fahrzeughülle 7 befestigt ist,
• - einen 3D-Beschleunigungs-Sensor 24,
• - einen Positions-Sensor 27,
• - einen Elektromotor 6,
• - eine Welle 9, die vom Elektromotor 6 gedreht wird,
• - einen Propeller 8, der auf der Welle 9 sitzt und mitsamt der Welle 9 gedreht wird,
• - eine Spannungsquelle 10, die den Elektromotor 6 elektrisch versorgt,
• - eine Antenne 26,
• - ein Steuergerät 20,
• - ein Datenspeicher-Rechner 21 und
• - einen Datenspeicher 22.

The underwater propulsion vehicle 1 is designed and comprised as an unmanned autonomous underwater vehicle (AUV)

• - a vehicle shell 7 ,
• - an upper rudder 4.1 and a lower rudder 4.2 which on the vehicle shell 7 are attached,
• - a left elevator 23.1 and a right elevator 23.2 , which is also on the vehicle shell 7 are attached,
• - a distance sensor 5 that is on the vehicle shell 7 is attached
• - a 3D acceleration sensor 24th ,
• - a position sensor 27 ,
• - an electric motor 6 ,
• - a wave 9 by the electric motor 6 is rotated
• - a propeller 8th who is on the wave 9 sits and together with the shaft 9 is rotated
• - a voltage source 10 that the electric motor 6 electrically powered,
• - an antenna 26 ,
• - a control unit 20 ,
• - a data storage calculator 21st and
• - a data storage 22 .

The data storage calculator 21st and the data store 22 together form the data storage unit of the embodiment.

• - einen Rumpf 13,
• - ein linkes Abstandselement in Form eines linken Flügels 14.1 und ein rechtes Abstandselement in Form eines rechten Flügels 14.2, die beide am Rumpf 13 befestigt sind,
• - ein oberes Tragelement 15.1 und ein unteres Tragelement 15.2, die ebenfalls beide am Rumpf 13 befestigt sind,
• - drei Abstands-Sensoren 11.1 bis 11.3,
• - einen 3D-Beschleunigungs-Sensor 25 und
• - vier Magnetometer 12.1 bis 12.4.

The underwater measuring body 2nd of the embodiment includes

• - a hull 13 ,
• - a left spacer in the form of a left wing 14.1 and a right spacer in the form of a right wing 14.2 both on the fuselage 13 are attached,
• - an upper support element 15.1 and a lower support member 15.2 both of which are on the fuselage 13 are attached,
• - three distance sensors 11.1 to 11.3 ,
• - a 3D acceleration sensor 25th and
• - four magnetometers 12.1 to 12.4 .

A front distance sensor 11.1 of the underwater measuring body 2nd is on the fuselage 13 attached, a left distance sensor 11.2 on the left wing 14.1 and a right distance sensor 11.3 on the right wing 11.2 . A left magnetometer 12.1 is on the left wing 14.1 mounted, a right magnetometer 12.2 on the right wing 14.2 , an upper magnetometer 12.3 on the upper support element 15.1 and a lower magnetometer 12.4 on the lower support element 15.2 . Preferably the two wings 14.1 and 14.2 the same dimension, so the four magnetometers 12.1 to 12.4 symmetrical to a central plane of the underwater measuring body 2nd are arranged. Preferably the hull 13 , the two wings 14.1 and 14.2 as well as the two support elements 15.1 and 15.2 made of a non-metallic material, for example made of glass fiber reinforced plastic (GRP).

An alternative embodiment is also possible, in which the underwater measuring body 2nd no spacers 14.1 , 14.2 and the two magnetometers 12.1 , 12.2 directly on the fuselage 13 are attached. It is also possible that the underwater measuring body 2nd no supporting elements 15.1 , 15.2 includes and the two magnetometers 12.3 , 12.4 directly on the fuselage 13 are attached.

The connecting element 3rd includes a flexible rope that connects to the underwater propulsion vehicle 1 and the underwater measuring body 2nd connected so that the underwater drive vehicle 1 the underwater measuring body 2nd able to move behind. In this rope is one Data line embedded, via which the data from the underwater measuring body 2nd to the underwater propulsion vehicle 1 are transmitted and there partly to the control unit 20 and partly to the data storage computer 21st be transmitted. In the exemplary embodiment, an activation command or a switch-off command is sent to the underwater measuring body if necessary 2nd transferred, but no data.

In the exemplary embodiment, the underwater measuring body has 2nd not its own drive, but is powered by the underwater drive vehicle 1 pulled through the water. The underwater measuring body 2nd of the exemplary embodiment also does not have its own voltage source, but is via the connecting element 3rd with electrical energy from the voltage source 10 of the underwater drive vehicle 1 provided. The two wings preferably change 14.1 and 14.2 as well as the two support elements 15.1 and 15.2 their respective position and dimensions relative to the fuselage 13 not while the arrangement is being used. It is possible that a wing or a support element is pushed together or folded away during the underwater measuring body 2nd is transported to an area of application. It is possible that at least one wing 14.1 , 14.2 can be pulled apart or pushed together telescopically before use by the distance between the magnetometers 12.1 and 12.2 to change.

In one embodiment, the underwater measuring body 2nd buoyancy-neutral, ie the buoyancy that that from the underwater measuring body 2nd displaced water is equal to the weight of the underwater measuring body 2nd (Buoyancy neutrality). If necessary, a buoyancy body (not shown) will be on board the underwater measuring body 2nd added, removed or changed. In another embodiment, the weight of the underwater measuring body is 2nd greater than the buoyancy. The two wings 14.1 and 14.2 generate a buoyancy when the underwater measuring body 2nd is moved through the water. This configuration enables the underwater measuring body 2nd to rise or fall in the water by changing the speed at which the underwater measuring body 2nd pulled through the water. This effect is achieved without the need for an intervention on the underwater measuring body 2nd make or the underwater measuring body 2nd change in any other way during use.

Any distance sensor 5 , 11.1 to 11.3 is designed as an altimeter and measures the distance between itself and the seabed without contact. For example, each distance sensor sends a pulse downwards. The seabed surface Mb reflects this pulse, the transit time is measured, and the distance sought is derived from the transit time. The three distance sensors 11.1 to 11.3 of the underwater measuring body 2nd are arranged in a triangle and therefore deliver three signals at each sampling time, which make up the current orientation of the underwater measuring body 2nd relative to the seabed surface Mb can be calculated, in particular the angle of rotation about the longitudinal axis, the angle of rotation about the transverse axis and the angle of rotation about the vertical axis of the underwater measuring body 2nd . The three distance sensors 11.1 to 11.3 thus function together as a position sensor for the underwater measuring body 2nd .

The optional 3D acceleration sensor 25th on board the underwater measuring body 2nd measures the respective acceleration of the underwater measuring body 2nd parallel to your own longitudinal axis, your own transverse axis and your own vertical axis. The 3D acceleration sensor 24th on board the underwater propulsion vehicle 1 measures the respective acceleration of the underwater propulsion vehicle 1 parallel to your own longitudinal axis, your own transverse axis and your own vertical axis. The position sensor 27 measures the direction in which the fastener 3rd away from the underwater propulsion vehicle 1 extends away.

In the example of 1 drives the underwater drive vehicle 1 due to the rotation of the propeller 8th completely below the water surface WHERE in one direction FR (in 1 from right to left). The rudder 4.1 , 4.2 and the elevator 23.1 , 23.2 control the drive of the underwater propulsion vehicle 1 . In one embodiment, the weight of the underwater drive vehicle 1 less than lift, and the elevator 23.1 and 23.2 hold the underwater propulsion vehicle 1 and thus the arrangement at a desired depth. If the drive of the underwater drive vehicle 1 fails, the arrangement rises up to the water surface WHERE and can be collected.

The underwater propulsion vehicle 1 travels along a predetermined route over the seabed surface Mb . In one embodiment, the antenna measures 26 from time to time the current geoposition of the underwater propulsion vehicle 1 , for example when the underwater propulsion vehicle 1 has surfaced or is at a shallow depth. The control unit 20 guides the current geoposition of the underwater propulsion vehicle 1 from the last measured geoposition and the signals from the 3D acceleration sensors 24th forth. It is also possible that on board the underwater propulsion vehicle 1 An interactive navigation system is available, so that the control unit 20 knows the current geoposition without the underwater propulsion vehicle 1 has to show up. In both embodiments, the control unit knows 20 to at least approximately the current geoposition at any time.

On the one hand, the arrangement should not collide with the sea floor during the journey. On the other hand, the distance between the underwater measuring body 2nd and the seabed be smaller than a predetermined barrier in order to be able to detect any object on or under the seabed surface with sufficient certainty Mb to actually find. The anomaly generated is known to decrease sharply as the distance between the object and a magnetometer increases.

The signals from the three distance sensors 11.1 to 11.3 as well as from the optional 3D acceleration sensor on board the underwater measuring body 2nd are about the fastener 3rd to the control unit 20 of the underwater drive vehicle 1 transmitted. In addition, the signals from the distance sensor 5 and optional further distance sensors (not shown) on board the underwater propulsion vehicle 1 also to the control unit 20 transmitted.

From the signals from the position sensor 27 determines the control unit 20 in which direction the connecting element 3rd extends. With the help of this measured direction, a lateral offset of the underwater measuring body can be achieved 2nd relative to the direction of travel FR determine. This lateral offset is caused in particular by a water flow near the surface of the sea floor Mb evoked. It is also possible to approximately determine how strong the connecting element is 3rd sags, which approximates the distance between the underwater propulsion vehicle 1 and the underwater measuring body 2nd can be determined. The control unit 20 determined from the signals from the two 3D acceleration sensors 24th , 25th the movement of the underwater measuring body 2nd relative to the underwater propulsion vehicle 1 . The control unit 20 controls the actuators for the two elevators depending on the signals from the distance sensors 23.1 and 23.2 to cause the distance between the ocean floor and the underwater measuring body 2nd on the one hand large enough and on the other hand smaller than the given barrier. The control unit 20 also controls actuators for the two rudders 4.1 and 4.2 as well as the electric motor 6 so the arrangement 1 , 2nd , 3rd drives through the water along a given route.

2nd shows a plan view of the underwater measuring body 2nd of the embodiment and the connecting element 3rd . The direction of travel FR is again from right to left. The left wing is shown schematically 14.1 , the right wing 14.2 as well as the two magnetometers 12.1 , 12.2 and the two distance sensors 11.2 and 11.3 on the two wings 14.1 , 14.2 . The two support elements 15.1 , 15.2 are perpendicular to the drawing plane of 2nd .

In 3rd becomes the underwater measuring body 2nd shown from the front. The longitudinal axis of the underwater measuring body 2nd and the direction of travel FR are perpendicular to the drawing plane of 3rd and point to the viewer. Both wings can be seen 14.1 , 14.2 , both support elements 15.1 , 15.2 as well as all four magnetometers 12.1 to 12.4 .

In the example of 3rd is the underwater measuring body 2nd rotated about 20 ° around its own longitudinal axis.

In one possible embodiment, each magnetometer is 12.1 to 12.4 designed for a total field measurement, it can only measure the size of an anomaly. In a preferred embodiment, each magnetometer 12.1 to 12.4 Conversely, it is designed as a three-axis magnetometer or four-axis magnetometer, for example as a flux gate, and is not only able to measure the size of an anomaly, but also the direction from the magnetometer to a source for the anomaly, i.e. to one discovering object. In 3rd are the four directions determined R.1 to R.4 of the four magnetometers 12.1 to 12.4 to the subject G shown. More specifically: the projections of the four directions R.1 to R.4 to the drawing level of 3rd are shown. Of course, one direction R.1 to R.4 also run at an angle to the plane of the drawing.

The signals from the four magnetometers 12.1 to 12.4 are from the underwater measuring body 2nd via the data line in the connecting element 3rd to the data storage computer 21st on board the underwater propulsion vehicle 1 transmitted. The data storage calculator 21st stores the signals from the magnetometers 12.1 to 12.4 in data storage 22 from.

The signals from the magnetometers 12.1 to 12.4 will be on the underwater propulsion vehicle 1 and there to the data storage computer 21st transmitted. The data storage calculator 21st stores the received signals in the data memory 22 from. The data storage computer preferably stores 21st for the measured and transmitted magnetometer signals an additional time stamp and the geoposition of the underwater measuring body 2nd at the time of measurement in the data memory 22 from, optionally also the cruising speed, the distance of the underwater measuring body 2nd to the seabed, the orientation of the underwater measuring body 2nd relative to the seabed surface Mb and / or the depth at the time of the measurement.

In one embodiment, the signals from the magnetometers 12.1 to 12.4 from an evaluation unit on board the underwater propulsion vehicle 1 evaluated. In the embodiment shown in the figures, however, the signals are on board the underwater propulsion vehicle 1 only stored, namely in data storage 22 , but not on board the underwater propulsion vehicle 1 evaluated. After the trip, the underwater drive vehicle 1 and the underwater measuring body 2nd fetched from the water. The data store 22 is read out, and the stored and read out signals, in particular the georeferenced magnetometer signals with the time stamps and further associated information, are sent to the evaluation unit 28 on board the ship S transmitted and from the evaluation unit 28 automatically evaluated.

On the one hand, the evaluation unit compares 28 the signals from two magnetometers each, which relate to the same point in time, carry out a total of six comparisons for each sampling point in time. If at least one comparison provides a significant difference, there is an anomaly and an object to be discovered G is located near the underwater measuring body at the time of measurement 2nd and creates this anomaly. Because with four magnetometers the two distances of the object G the anomalies differ by at least two magnetometers. Or the object G causes an anomaly only in the magnetic field around one magnetometer, but not in the magnetic field around another magnetometer. Because the underwater measuring body 2nd four magnetometers 12.1 to 12.4 has, which are not all in the same plane, the arrangement can with greater certainty an object G to discover and locate as if fewer than four magnetometers were used. Redundancy is also provided in the event that a magnetometer fails.

The evaluation unit preferably determines 28 approximate the current direction from the underwater measuring body 2nd to the subject G and the distance between the object G and the underwater measuring body 2nd . The evaluation unit uses this 28 the signals from each magnetometer 12.1 to 12.4 that discovered an anomaly and therefore determined a direction to the source of that anomaly. In the example of 3rd have all four magnetometers 12.1 to 12.4 one direction each R.1 to R.4 to the subject G determined. Ideally, the four directional vectors intersect R.1 to R.4 itself in one point, and that point belongs to the object G . The evaluation unit 28 also evaluates the signals from the distance sensors 11.1 to 11.3 on board the underwater measuring body 2nd to the current position (orientation) of the underwater measuring body 2nd to determine in the water. The evaluation unit uses this determined position 21st to the direction of the object G to investigate.

• - die aktuelle Geoposition des Unterwasser-Antriebsfahrzeugs 1,
• - die aktuelle Position des Unterwasser-Messkörpers 2 relativ zum Unterwasser-Antriebsfahrzeug 1,
• - die Richtung und Entfernung des Gegenstands G bezogen auf den Unterwasser-Messkörper 2, ermittelt unter Verwendung der vier Richtungen R.1 bis R.4, und
• - optional die Fahrgeschwindigkeit des Unterwasser-Antriebsfahrzeugs 1, welche aus Signalen des 3-D-Beschleunigungs-Sensors 24 berechnet wird.

The evaluation unit 28 determines the geoposition of the object G and optionally a position and / or orientation of the object G relative to the seabed surface Mb . The evaluation unit uses this 28 following informations:

• - the current geoposition of the underwater propulsion vehicle 1 ,
• - the current position of the underwater measuring body 2nd relative to the underwater propulsion vehicle 1 ,
• - the direction and distance of the object G related to the underwater measuring body 2nd , determined using the four directions R.1 to R.4 , and
• - optionally the driving speed of the underwater drive vehicle 1 , which consists of signals from the 3-D acceleration sensor 24th is calculated.

In one embodiment, the evaluation unit guides 28 from the signals from the magnetometer 12.1 to 12.4 at least one property of the item G from, for example, what material the item is made of G and how big it is and / or what shape it is.

• - die Geoposition des Gegenstands G, welche die Auswerteeinheit 21 so wie oben beschrieben ermittelt hat,
• - die Tiefe des Gegenstands G unter der Meeresboden-Oberfläche Mb,
• - ermittelte Eigenschaften des Gegenstands und / oder
• - ein Zeitstempel, also die Information, wann die Magnetometer 12.1 bis 12.4 die Anomalien gemessen haben, die der Gegenstand G im Magnetfeld hervorruft.

The evaluation unit 28 stores information about a determined object in a data memory (not shown) on board the ship S from and / or output it in a form that can be grasped by a person. This information includes

• - the geoposition of the object G which the evaluation unit 21st determined as described above,
• - the depth of the object G under the seabed surface Mb ,
• - determined properties of the object and / or
• - a time stamp, i.e. the information when the magnetometer 12.1 to 12.4 have measured the anomalies that the object G in the magnetic field.

In one embodiment, the signals are already on board the underwater propulsion vehicle 1 evaluated, and the underwater drive vehicle 1 transmits this information about the item G wirelessly to a remote platform. For this, the underwater propulsion vehicle dives 1 or at least goes into a shallower water and sends the information about the Object using the antenna 26 out. The step, the information on the object G To transmit, one embodiment is triggered by an evaluation unit on board the underwater drive vehicle 1 an object G with certain predefined properties. If the evaluation unit has not discovered such an object during the journey, the underwater drive vehicle transmits 1 In one embodiment, information about discovered objects is wirelessly transmitted to a spatially distant platform at the end of the journey.

In one embodiment, the underwater drive vehicle becomes after the journey 1 and the underwater measuring body 2nd on board a platform, for example on board the ship S , added, and the data storage 22 is read out. The two configurations, the information to be transmitted and the data storage 22 can be read out, combined, so that the determined information about objects is available even if the underwater drive vehicle fails 1 to resume on board the platform.

The evaluation unit is in the embodiment just described 28 on board the underwater propulsion vehicle 1 arranged and evaluates the signals from the magnetometers 12.1 to 12.4 already off while the arrangement runs through the water. This configuration makes it possible to set a message about the discovery of an object with certain properties while the arrangement is in motion.

In another embodiment, the evaluation unit 28 arranged on board a spatially distant platform, for example on board the surface ship S . The signals from the magnetometers 12.1 to 12.4 are in data storage 22 stored and not on board the underwater propulsion vehicle 1 evaluated. Rather, the evaluation unit evaluates 21st on board the platform S the signals from the magnetometers 12.1 to 12.4 out after the underwater propulsion vehicle 1 on board the platform S was taken and the data storage 22 was read out. This configuration saves the need for an evaluation unit 21st on board the underwater propulsion vehicle 1 to have to provide.

Reference list

1

Underwater propulsion vehicle in the form of an unmanned autonomous underwater vehicle (AUV), includes the rudder 4.1 , 4.2 who have favourited Elevators 23.1 , 23.2 , the distance sensor 5 , the electric motor 6 who have favourited Vehicle Skin 7 , the propeller 8th , the wave 9 , the voltage source 10 , the control unit 20 , the data storage calculator 21st and the data storage 22

2nd

Underwater measuring body, includes the distance sensors 11.1 to 11.3 who have favourited Multi-Axis Magnetometers 12.1 to 12.4 , the fuselage 13 , the wings 14.1 , 14.2 and the support elements 15.1 , February 15

3rd

Connecting element in the form of a rope with a cable, which connects the underwater measuring body 2nd with the underwater drive vehicle 1 connects

4.1

upper rudder of the underwater propulsion vehicle 1

4.2

lower rudder of the underwater propulsion vehicle 1

5

Distance sensor of the underwater drive vehicle 1 , measures the distance between itself and the seabed surface Mb

6

Electric motor of the underwater drive vehicle 1 , turns the shaft 9 , from the voltage source 10 electrically supplied

7

Vehicle casing of the underwater drive vehicle 1

8th

Propeller of the underwater propulsion vehicle 1 , sits on the wave 9

9

Wave of the underwater drive vehicle 1 , from the electric motor 6 rotated, rotates the propeller 8th

10th

Power source on board the underwater propulsion vehicle 1 , electrically supplies the electric motor 6

11.1

Front distance sensor of the underwater measuring body 2nd , on the fuselage 13 attached, measures the distance to the seabed surface Mb

11.2

left distance sensor of the underwater measuring body 2nd , on the left wing 14.1 attached, measures the distance to the seabed surface Mb

11.3

right distance sensor of the underwater measuring body 2nd , on the right wing 14.2 attached, measures the distance to the seabed surface Mb

12.1

left magnetometer of the underwater measuring body 2nd , on the left wing 14.1

12.2

attaches right magnetometer of the underwater measuring body 2nd , on the right wing 14.2 attached

12.3

upper magnetometer of the underwater measuring body 2nd , on the upper support element 15.1 attached

12.4

lower magnetometer of the underwater measuring body 2nd , on the lower support element 15.2 attached

13

Hull of the underwater measuring body 2nd , carries the two wings 14.1 and 14.2 and the two support elements 15.1 and 15.2

14.1

left wing of the underwater measuring body 2nd , carries the left magnetometer 12.1 and the left distance sensor 11.2

14.2

right wing of the underwater measuring body 2nd , carries the right magnetometer 12.2 and the right distance sensor 11.3

15.1

upper support element, on the fuselage 13 attached, carries the upper magnetometer 12.3

15.2

lower support element, on the fuselage 13 attached, carries the lower magnetometer 12.4

20

Control unit of the underwater drive vehicle 1 , receives signals from the distance sensors 5 and 11.1 to 11.3 and controls the rudder 4.1 and 4.2 as well as the electric motor 6 on

21

Data storage computer on board the underwater propulsion vehicle 1 , receives signals from the magnetometers 12.1 to 12.4 and stores the received signals georeferenced in the data memory 22 from

22

Data storage of the underwater drive vehicle 1 , is from the data storage computer 21st filled with measurement results

23.1,

Elevator of the underwater propulsion vehicle 1

23.2

24th

3D acceleration sensor on board the underwater propulsion vehicle 1

25th

3D acceleration sensor on board the underwater measuring body 2nd

26

optional underwater aerial of the underwater propulsion vehicle 1

27

Position sensor on board the underwater propulsion vehicle 1 , measures the direction of the connector 3rd on the underwater drive vehicle 1

28

Evaluation unit on board the ship S

FR

Direction of travel of the arrangement 1 , 2nd , 3rd through the water

G

Object to be discovered under the seabed surface Mb

Mb

Surface of the sea floor under which the object is G located

R.1, ...,

Directions to the object G , from the magnetometers 12.1 to 12.4

R.4

measured

S

Ship with the evaluation unit 28

WHERE

Water surface under which the arrangement 1 , 2nd , 3rd located

Claims (19)

Arrangement for locating an object (G) which is located in or under a body of water, the arrangement - an underwater drive vehicle (1) with a drive (6, 8, 9) and a direction change unit (4.1, 4.2 , 23.1, 23.2), - an underwater measuring body (2) spaced from the underwater driving vehicle (1), - a connecting element (3) which connects the underwater driving vehicle (1) to the underwater measuring body (2), and - comprises a data storage unit (21, 22), the underwater measuring body (2) comprising - a first magnetometer (12.1) and - a second magnetometer (12.2, ...), the arrangement being designed for use under water, wherein each magnetometer (12.1, 12.2, ...) is designed to measure a size that corresponds to the Magnetic field correlates with this magnetometer (12.1, 12.2, ...), and the data storage unit (21, 22) is designed to automatically store signals from the two magnetometers (12.1, 12.2, ...). Arrangement after Claim 1 , characterized in that the arrangement further comprises an evaluation unit (28) which is designed to evaluate automatically stored signals from the two magnetometers (12.1, 12.2, ...). Arrangement after Claim 2 , characterized in that the evaluation unit (28) is designed to detect and evaluate a difference between the signals from the two magnetometers (12.1, 12.2, ...). Arrangement according to one of the preceding claims, characterized in that each magnetometer (12.1, 12.2, ...) is designed as a multi-axis magnetometer, in particular as a three-axis or four-axis magnetometer. Arrangement according to one of the preceding claims, characterized in that the underwater measuring body (2) has a third magnetometer (12.3), the third magnetometer (12.3) - seen in the direction of travel (FR) of the arrangement through the water - between the first magnetometer (12.1) and the second magnetometer (12.2). Arrangement after Claim 2 and after Claim 5 , characterized in that the evaluation unit (28) is designed to detect a difference between - the signals of the third magnetometer (12.3) on the one hand and - the signals of the first magnetometer (12.1) and / or the second magnetometer (12.2) on the other. Arrangement according to one of the preceding claims, characterized in that the underwater measuring body (2) comprises a fourth magnetometer (12.4) which, when the underwater measuring body (2) is used regularly, has a smaller distance from the surface (Mb) of the water floor than that first magnetometer (12.1) and the second magnetometer (12.2). Arrangement according to one of the preceding claims, characterized in that the underwater measuring body (2) comprises at least one distance sensor (11.1, 11.2, 11.3), the or each distance sensor (11.1, 11.2, 11.3) being designed to measure the distance between the underwater measuring body (2) and a body of water, the underwater measuring body (2) being designed to send signals from the or each distance sensor (11.1, 11.2, 11.3) to the underwater drive vehicle (1 ) and the underwater drive vehicle (1) is designed to move the arrangement depending on signals from the or each distance sensor (11.1, 11.2, 11.3) through the water. Arrangement according to one of the preceding claims, characterized in that the underwater measuring body (2) comprises a position sensor (11.1, 11.2, 11.3) which is designed to measure the position of the underwater measuring body (2) in the water, the data storage unit (21, 22) being designed to store signals from the position sensor (11.1, 11.2, 11.3) associated with signals from the magnetometers (12.1, 12.2, ...). Arrangement after Claim 2 and after Claim 9 , characterized in that the evaluation unit (28) is designed to evaluate signals from the position sensor (11.1, 11.2, 11.3) when evaluating the signals from the two magnetometers (12.1, 12.2, ...). Arrangement according to one of the preceding claims, characterized in that the data storage unit (21, 22) is arranged on board the underwater drive vehicle (1) and the underwater measuring body (2) is designed to receive signals from the two magnetometers (12.1 , 12.2, ...) to the data storage unit (21, 22) on board the underwater propulsion vehicle (1). Arrangement according to one of the preceding claims, characterized in that the underwater measuring body (2) comprises - a hull (13), - a first spacer (14.1) and - a second spacer (14.2), the two spacers (14.1, 14.2 ) are attached to the fuselage (13), the fuselage (13) being located between the two spacers (14.1, 14.2), the first magnetometer (12.1) being attached to the first spacer (14.1) and wherein the second magnetometer (12.2) is attached to the second spacer (14.2). Arrangement after Claim 12 , characterized in that the two spacers (14.1, 14.2) - are designed as wings and - are mounted on the fuselage (13) in such a way that they generate buoyancy when the underwater measuring body (2) is moved by the water. Arrangement according to one of the preceding claims, characterized in that the arrangement comprises a movement sensor (24, 25) which is designed to measure a movement of the underwater measuring body (2) relative to the underwater propulsion vehicle (1). Arrangement according to one of the preceding claims, characterized in that the distance between the two magnetometers (12.1, 12.2, ...) is variable. Use of an arrangement according to one of the preceding claims, for locating metallic objects (G) which are located below the surface (Mb) of the body of water. Method for locating an object (G) located in or under a body of water using an arrangement which - An underwater drive vehicle (1) with a drive (6, 8, 9) and a direction change unit (4.1, 4.2, 23.1, 23.2), an underwater measuring body (2) spaced from the underwater drive vehicle (1), - A connecting element (3), which connects the underwater drive vehicle (1) with the underwater measuring body (2), and - a data storage unit (21, 22) includes, the underwater measuring body (2) - a first magnetometer (12.1) and - a second magnetometer (12.2, ...) includes, the method comprising the steps of: the arrangement is moved under water through the water, - each magnetometer (12.1, 12.2, ...) measures a quantity which correlates with the magnetic field around this magnetometer (12.1, 12.2, ...), and - The data storage unit (21, 22) automatically stores signals from the two magnetometers (12.1, 12.2, ...). Procedure according to Claim 17 , characterized in that the arrangement comprises an evaluation unit (28) and the method comprises the further steps that - the signals stored by the data storage unit (21, 22) are transmitted to the evaluation unit (28) and - the evaluation unit (28 ) automatically evaluates the transmitted signals. Procedure according to Claim 18 , characterized in that the data storage unit (21, 22) is on board the underwater drive vehicle (1), the signals from the underwater measuring body (2) are transmitted to the underwater drive vehicle (1) and the step which to transmit stored signals to the evaluation unit (28) is carried out after the underwater drive vehicle (1) has been removed from the water.

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