The present invention relates to the general field of sonar detection in particular implemented in anti-submarine warfare. It relates more particularly to the field of airborne sonars called "dipped sonars" or

"dipping sonar" in the Anglo-Saxon literature implemented from a helicopter or a drone.

[0002] In the context of anti-submarine warfare activities, in order to be able to detect submarines submerged in a given area, recourse is generally had to the use of sonars, in particular active sonars. In this context, the

deployment of sonars from aerial platforms, helicopters or drones, proves to be particularly effective because such platforms have great mobility compared to submarines.

More specifically, helicopters are used to implement sonar transmitters and receivers connected by a cable to their platform, in other words to the helicopter. We then speak of "dipped sonars". Subsequently, the sub-assembly submerged and connected by the cable is called antenna. It includes the actual sonar transmitters and receivers and possibly electronic equipment associated with the transmitters and receivers. It may also include environment sensors.

[0004] In known manner, the launching from the platform, the immersion control as well as the recovery on board of these antennas are carried out by means of a winch located inside the helicopter.

[0005] During the descent and the ascent of the antenna by means of the winch, the cable generates significant drag in the water. This drag increases with the depth reached by the antenna due to the length of cable unwound. The rate of descent and ascent of the antenna is thus limited by the drag generated by the movement of the cable. The greater the depth, the more the speed must be reduced on the descent because the antenna is dragged down only by its reduced weight of its own drag and that of the cable. On ascent, the winch must exert on the cable a force equal to the weight of the antenna increased by the overall drag. It would be possible to provide a winch capable of withstanding significant drag. The cable must be sized to withstand the pulling force exerted by the winch.

The greater this force, the more the section of the cable must be increased, which again tends to increase the drag.

The invention aims to make a detection operation by means of a dipped sonar independent of the drag of the cable. By detection operation is meant the lowering of the antenna, the actual acoustic detection phase and the raising of the antenna.

To this end, the invention relates to a dipped sonar comprising an antenna equipped with acoustic transmitters and receivers. The dip sonar further includes a motorized winch having a reel, an actuator configured to rotate the reel, and a cable wound on the reel. The winch is arranged in the antenna and the cable makes it possible to hook the antenna to a carrier at a free end of the cable.

[0008] The antenna may comprise deployable arms on which the acoustic receivers are arranged, the deployable arms being articulated with respect to a casing of the antenna and a body movable in translation with respect to the casing along a main axis of the cable. The arms are then articulated relative to the body. In a first position of the body, in its translation relative to the casing, the arms are folded against the casing and in a second position of the body in its translation relative to the casing, the arms are deployed.

The antenna may comprise several rings each carrying acoustic transmitters, a body movable in translation relative to the housing along a main axis of the cable. The rings and the body are advantageously interconnected by means of extensible links. In a first position of the body in its translation relative to the housing, the rings and the body are in contact with each other and in a second position of the body in its translation relative to the housing, the rings and the body are distant from each other others.

The body is advantageously provided with a clamp configured to clamp the cable, allowing, in an open position of the clamp, the body to occupy its first position and allowing, in a closed position of the clamp, the body of occupy his second position.

[001 1] The antenna advantageously comprises a battery and means for recharging the battery not passing through the cable, the battery making it possible to supply the acoustic transmitters and the actuator.

[0012] The antenna advantageously comprises at least one energy converter making it possible to supply either the acoustic transmitters or the actuator.

[0013] The energy converter is advantageously bidirectional allowing either the battery to power the actuator or the actuator to recharge the battery.

The invention will be better understood and other advantages will appear on reading the detailed description of an embodiment given by way of example, description illustrated by the attached drawing in which:

[0015] Figures 1a and 1b show different carriers each equipped with a dipped sonar;

[0016] FIG. 2 represents a first alternative embodiment of an antenna of the dipped sonar of FIGS. 1a and 1b;

[0017] Figures 3a and 3b show a second alternative embodiment of an antenna of the dipped sonar of Figures 1a and 1b;

[0018] Figures 4a and 4b show a third alternative embodiment of an antenna of the dipped sonar of Figures 1a and 1b;

Figure 5 shows in the form of a block diagram an example of electrical architecture of a dipped sonar antenna.

[0020] For the sake of clarity, the same elements will bear the same references in the various figures.

[0021] Figure 1a shows a drone 10 hovering above the water, the surface of which bears the mark 11. The drone 10 is equipped with a dipped active sonar comprising an antenna 12 attached to the drone 10 by a cable 14. This type of sonar allows in particular the detection and classification of underwater objects. FIG. 1b represents a helicopter 16 also equipped with a dipped active sonar comprising the antenna 12 attached to the helicopter 16 by the cable 14.

In general, in the context of the invention, any type of carrier capable of positioning itself above the water can be equipped with a dipped active sonar. The wearer is able to lower the antenna to a desired depth of immersion, to control the acoustic detection phase and to raise the antenna in order to complete its mission or in order to carry out other detection operations.

[0022] Figure 2 shows a first antenna embodiment 20 of a hardened active sonar according to the invention. Antenna 20 is equipped with transmitters

acoustic receivers 22, acoustic receivers 24 as well as a motorized winch 26. The winch 26 makes it possible to wind and unwind the cable 14. A free end 27 of the cable 14 makes it possible to attach the antenna 20 to the carrier such as the drone 10 or helicopter 16. Antenna 20 extends along an axis 28 which is vertical when antenna 20 is hung by cable 14 and is only subject to gravity. The antenna 20 has a shape substantially of revolution around the axis 28. The acoustic transmitters 22 and the acoustic receivers 24 are arranged radially around the axis 28.

[0023] Les émetteurs acoustiques 22 et les récepteurs acoustiques 24 peuvent être fixés à un boîtier 29 de l’antenne 20. Les émetteurs acoustiques 22 et les récepteurs acoustiques 24 peuvent être disposés dans des zones distinctes de l’antenne 20, les zones étant superposées l’une au-dessus de l’autre comme représenté sur la figure 2. Alternativement, les zones peuvent être imbriquées comme par exemple décrit dans la demande de brevet publiée sous le n° WO2015/092066 et déposée au nom de la demanderesse.

[0024] Le treuil 26 est motorisé au moyen d’un actionneur 30. Plus précisément, l’actionneur 30 permet de faire tourner un touret 32 sur lequel le câble 14 est enroulé. L’actionneur 30 peut être un moteur électrique, hydraulique ou de façon plus générale mettant en oeuvre toute forme d’énergie apte à fonctionner dans un espace confiné sans renouvellement d’air. Il est avantageusement situé à l’intérieur du touret 32 afin de libérer de l’espace dans l’antenne 20. Le câble 14, sur sa partie déroulée, s’étend selon l’axe vertical 28. L’antenne 20 pend sous l’effet de la gravité. Sur la figure 2, le touret 32 tourne autour d’un axe horizontal 34. Alternativement, le câble 14 peut s’enrouler autour d’un touret à axe vertical. Un mécanisme de trancannage permet de ranger le câble 14 sur le touret 32. Le mécanisme de trancannage assure une translation alternée d’un guide câble le long de l’axe du touret afin de ranger le câble 14 en couches successives sur le touret 32. Dans le cas d’un touret à axe

vertical, le touret peut être fixe et le mécanisme de trancannage tourne alors autour du touret en complément de sa translation. De tels mécanismes existent notamment dans les moulinets de pêche. Alternativement, le touret peut tourner autour de son axe et le guide du mécanisme de trancannage ne se déplace qu’en translation par rapport à un boîtier 29 de l’antenne 20.

[0025] Le treuil 26 formé du touret 32 et de l’actionneur 30 est disposé à l’intérieur de l’antenne 20, par exemple dans un volume interne 36 située entre les récepteurs acoustiques 24.

[0026] L’antenne 20 comprend également des modules électroniques 38 permettant notamment la génération des signaux acoustiques émis par les émetteurs 22, le traitement des signaux acoustiques reçus par les récepteurs 24 et le pilotage de l’actionneur 30.

[0027] L’énergie électrique nécessaire au fonctionnement de tous les composants de l’antenne 20 peut provenir du porteur et être véhiculée par le câble 14. Cependant cette solution nécessite d’augmenter la section du câble 14 pour être à même de véhiculer toute l’énergie nécessaire. En particulier, l’alimentation des émetteurs acoustiques nécessite une puissance instantanée importante qui peut être de l’ordre de plusieurs kilowatts. Le câble 14 pouvant dépasser plusieurs centaines de mètres de long, il est alors nécessaire de prévoir une section de câble suffisamment importante pour limiter les effets de pertes ohmiques le long du câble 14. Cela tend à augmenter les dimensions du touret 32 qui doit pouvoir accueillir le câble 14 dans la quasi-totalité de sa longueur. De plus, durant les phases d’émissions acoustiques, la transmission de données dans le câble doit être interrompue pour éviter toute perturbation des données lors de la transmission de puissance dans le câble 14.

To limit the periods of high power transfer in the cable 14, it is advantageous that the antenna 20 is equipped with a battery 40 advantageously disposed in a lower part of the antenna 20 or at least under the volume 36 containing the winch 26 in order to allow the antenna to maintain a better vertical orientation, in particular during the descent when it is hung by the cable 14. The battery 40 can be intended to smooth the transfer of electrical energy in the cable 14, which makes it possible to reduce the section of the electrical conductors of the cable 14. To this end, the battery 40 can supply the acoustic transmitters 22 which usually emit at high power during a small fraction of the duration of a mission. It is also advantageous to completely dispense with energy transfer in the cable 14.

antenna, such as the winch 26, the electronic modules 38, the transmitters 22 and acoustic receivers 24. For recharging the battery 40, the antenna comprises recharging means independent of the cable 14, such as specific connector or a zone of

contactless charging 42, for example by induction. The recharging of the battery 40 can be done on board the carrier 10 or 16 by connecting the specific connector or by placing the zone 42 close to a dedicated inductor.

The antenna 20 can also include environmental sensors such as a depth sounder 44 for determining the distance from the antenna 20 to the bottom and a temperature sensor 46 for measuring changes in water temperature. depending on the depth reached by the antenna 20. Indeed, the

propagation of sound waves in water is a function of the evolution of the

water temperature. These sensors can also be powered by battery 40.

Figures 3a and 3b show a second antenna embodiment 50 of a dipped active sonar according to the invention. In this variant during sonar reception, the acoustic receivers 24, possibly placed on arms, are deployed at a distance from the housing 29 of the antenna 50. On the other hand during the

operation of the winch 26, the acoustic receivers 24 are arranged against the casing 29 in order to limit the drag of the antenna 50 during the descent and the ascent of the antenna 50 in the water. This type of deployable antenna was developed in the past by the applicant. In this type of antenna, the deployment of the acoustic receivers is carried out by means of an electromechanical mechanism placed in the antenna. This mechanism includes an electric motor moving arms supporting the acoustic receivers. The motor is activated both during deployment and during folding of the arms. This mechanism is heavy and bulky.

[0031] Within the general framework of the invention, it is possible to keep in the antenna such an electromechanical arm maneuver mechanism supporting the acoustic receivers 24. Alternatively, the second variant makes it possible to dispense with this mechanism.

The antenna 50 comprises deployable arms 52 on which the acoustic receivers 24 are arranged. The arms 52 are advantageously distributed evenly around the axis 28 in order to ensure complete acoustic detection around the axis 28 Figure 3a partially shows the antenna 50 in which the arms 52 are folded against the housing 29. Figure 3b also partially shows the antenna 50 in which the arms 52 are deployed at a distance from the housing 29. The arms 52 are articulated with respect to the housing 29 and with respect to a body 54 forming a cover in the form of a washer and mobile in translation with respect to the housing 29 along the axis 28. The body 54 is for example of revolution around the axis 28 and the cable 14 passes through body 54 through the hole in the washer.

[0033] This double articulation allows the arms 52 to move away from or approach the housing 29 when the body 54 moves. More specifically, in the position of the body 54 shown in FIG. 3a, the arms 52 are folded housing 29 and in the position of the body 54 shown in Figure 3b, the arms 52 are deployed away from the housing 29.

The arms 52 can be articulated directly on the housing 29 and on the body 54 by means of pivot links. Once deployed, the arms 52 extend horizontally or inclined relative to the axis 28. The kinematics of this type of mechanism is very simple. It is used in particular in sonar buoys where the wearer floats on the surface of the water. However, this orientation of the arms can degrade the acoustic detection when the wearer is a drone or a helicopter.

Indeed, in this orientation, the acoustic receivers 24 are disturbed by the noise generated by the wearer. It may therefore be preferable to provide a vertical orientation of the arms 52 when they are deployed. In other words, it may be desirable to keep the arms parallel to the axis 28 during the translation of the body 54. To do this, the arms 52 can be articulated via a deformable parallelogram. More specifically, two bars 56 and 58 having parallel sections are articulated on the one hand on an arm 52, respectively by means of links 60 and 62, and on the other hand on the housing 29, respectively by means of links 64 and 66 One of the bars, bar 58 in the example shown, is articulated to the body 54 by means of the link 68 at a point distant from its articulation to the arm 52 and from its articulation to the housing 29. Thus, when the body 54 moves in translation, the bar 58 pivots around its articulation to the housing 29 and drives the arm 52. The bar 56 is driven by the arm 52 and also pivots relative to the housing 29. During this movement, the orientation of the arm 52 relative to the housing 29 does not vary. In the example shown, arm 52 remains parallel to axis 29.

Comme représenté, il est possible d’articuler plusieurs bras 52, deux dans l’exemple représenté, aux deux mêmes barres 56 et 58. Plus précisément, chacun des deux bras 52 est articulé à la barre 58 et à la barre 56. Comme précisé plus haut, l’antenne 50 peut être équipée de plusieurs bras 52 répartis autour de l’axe 28. Pour supporter ces différents bras 52, plusieurs séries de deux barres 56 et 58 réparties elles aussi de façon radiale autour de l’axe 28 équipent l’antenne 50.

[0035] Le déplacement du corps 54 en translation par rapport au boîtier 29 peut être réalisé au moyen d’un actionneur électromécanique assurant directement ce déplacement. L’actionneur est par exemple formé d’un vérin linéaire dont le corps est fixé au boîtier 29 et dont la tige, se déplaçant en translation par rapport au corps du vérin, est fixée au corps 54. Le montage inverse est également possible.

[0036] Avantageusement, il est possible de se passer d’actionneur entre le boîtier 29 et le corps 54 en utilisant les forces de gravité s’exerçant sur le boîtier 29 et sur le corps 54. En effet, le boîtier 29 peut contenir des composants lourds qui peuvent être mis à profit pour le déploiement des bras 52. Pour ce faire, le corps 54 est muni d’une pince 70 configurée pour pincer le câble 14 et l’immobiliser par rapport au corps 54. La pince 70 peut être manœuvrée par un actionneur électromécanique.

Cet actionneur lié au corps 54 consomme nettement moins d’énergie qu’un actionneur assurant directement le déplacement du corps 54 par rapport au boîtier 29.

[0037] En position ouverte de la pince 70, le câble 14 est libre par rapport au corps 54 et son poids, associé à celui des bras 52 par l’intermédiaire de l’articulation 68, entraîne le corps 54 vers le bas, c'est-à-dire vers le boîtier 29. Dans cette position, les bras 52 sont également entraînés vers le bas, c'est-à-dire en position repliée contre le boîtier 29. Cette position, pince ouverte, est représentée sur la figure 3a.

[0038] En position fermée de la pince 70 le câble 14 est immobilisé par rapport au corps 54. Dans cette position, il est possible de manoeuvrer le treuil 26 de façon à dérouler le câble et ainsi permettre au boîtier 29 et aux équipements qui lui sont fixé de descendre par rapport au corps 54 sous l’effet de la gravité. Ce mouvement relatif du corps 54 par rapport au boîtier 29 entraîne le déploiement des bras 52 pour atteindre la position de la figure 3b. Ceci est possible si les bras 52, et le cas échéant les barres 56 et 58, sont plus légers que le boîtier 29 et tous les composants qui lui sont fixés. Cette condition est généralement facilement respectée du fait de la présence de composants lourds dans le boîtier 29, notamment la batterie 40 et le treuil 26. La manoeuvre du treuil 26 pour dérouler le câble 14 après la fermeture de la pince 70 se fait de manière coordonnée avec le déplacement relatif du corps 54 par rapport au boîtier 29. Plus précisément, la longueur de câble déroulée est

substantially equal to the length of the translation of the body 54 relative to the housing 29. Unrolling a greater length of cable would risk causing the presence of a slack cable between the reel 32 and the clamp 70. Unrolling a shorter length of cable does not allow not to fully deploy the arms 52. It is possible to control the deployment of the arms 52 by operating the winch 26.

The clamp 70 comprises a fixed part integral with the body 54 and a movable part relative to the fixed part and coming into contact with the cable 14. The fixed part of the clamp 70 can be integral with the body 54 or optionally floating. More specifically, in the open position of the clamp 70, the fixed part can retain at least one degree of freedom in translation along the axis 28 relative to the body 54. This degree of freedom facilitates the closing of the clamp 70 when the antenna 50 is downhill or uphill. This degree of freedom makes it possible to limit the friction of the mobile part on the cable 14 when the clamp 70 is closed.

[0040] FIGS. 4a and 4b represent a third alternative embodiment of the antenna 80 of a hardened active sonar according to the invention. In this variant, we find the box 29 in which the winch 26 is located, the arms 52 articulated on the box 29 by means of the bars 56 and 58. As for FIG. 3a, FIG. 4a represents the arms 52 in position folded against the housing 29. Similarly, as for Figure 3b, Figure 4b shows the arms 52 in the deployed position.

[0041] Unlike the second variant, the antenna 80 of the third variant comprises a body made in two parts, a lower part forming a tube 82 around the axis 28 and movable in translation relative to the housing 29 according to the axis 28 and an upper part forming a cover 84 in the form of a washer similar to the body 54. The cable 14 passes through the cover 84 also through the hole in the washer.

The bar 58 is articulated to the tube 82 by means of the connection 68 at a point distant from its articulation to the arm 52 and from its articulation to the housing 29. Thus, when the tube 82 moves in translation, the bar 58 pivots around its articulation to the housing 29 and drives the arm 52.

The cover 84 is movable in translation relative to the tube 82 along the axis 28. The cover 84 is connected to the tube 82 by means of an extensible link. The antenna 80 also includes the clamp 70. As in the second variant, the clamp 70 of the antenna 80 is configured to clamp the cable 14 and thus make it possible to immobilize the cable 14 with respect to the cover 84 when the clamp is closed. In the position of Figure 4a, the clamp 70 is open and the cover 84 is placed on the tube 82 which is placed in turn on the housing 29. The cover 84 and the tube 82 are driven by gravity. In the position of Figure 4b, clamp 70 is closed and gravity pulls housing 29 down and holds cover 84 away from tube and tube 82 away from housing 29.

In the antenna 20, the acoustic transmitters 22 are attached to the housing 29. The transmitters occupy a predefined height along the axis 28. It can be

advantageous to increase this height, in particular to separate the transmitters vertically from each other. However, such a difference also tends to increase the height of the antenna 20 along its axis 28. The antenna 80 offers an alternative making it possible to maintain a given height between the acoustic transmitters during the descent and ascent of the antenna and extend this height during the detection phase. In other words the antenna 80 is configured to allow the

deployment of the transmitters along the axis 28 during the detection phase.

For this purpose, the antenna 80 comprises several rings 90 each carrying acoustic transmitters 22. The rings 90 can slide along the axis 28 between the housing 29 and the cover 84. The rings 90 are interconnected by means of extensible links 92 along the axis 28. Thus, in the position of FIG. 4a, when the antenna 80 descends or rises towards the wearer, the rings 90 are in contact with each other, stored inside of the tube 82. In addition, the arms 52 are folded as in Figure 3a. In this position the antenna 80 occupies a compact volume generating minimal drag during the descent or the ascent of the antenna 80. In the position of FIG. 4b, the arms 52 are deployed as in FIG. 3b and the rings 90 are also deployed. Specifically, 90 rings are

distant from each other. Rings 90 are also spaced apart from cover 84 and tube 82.

In the example shown in Figures 4a and 4b, the antenna 80 comprises four rings 90. In Figures 4a and 4b the rings 90 are differentiated and carry the pins 90a, 90b, 90c and 90d. Similarly the extensible links 92 are differentiated and bear the marks 92a, 92b, 92c, 92d and 92e. It is understood that the invention can be implemented regardless of the number of rings 90 with a corresponding number of expandable links. More precisely, an extensible link 92a connects the cover 84 to the ring 90a. An extendable link 92b connects ring 90a to ring 90b. An extendable link 92c connects ring 90b to ring 90c. An expandable link 92d connects ring 90c to ring 90d and an expandable link 92e connects ring 90d to tube 82. In the configuration of Figure 4a the extensible links 92a to 92e are relaxed and allow the positioning of the rings 90a to 90d in contact with each other. In the configuration of Figure 4b the extensible links 92a to 92e are stretched and allow the positioning of the rings 90a to 90d separated from each other and separated from the cover 84 and the tube 82. The extensible links 92a to 92e are for example made in means of straps which, in the stretched position, determine the spacing of the rings between them and with respect to the cover 84 and to the tube 82. In the position of FIG. 4a, the straps are simply relaxed and are stored inside the rings.

[0046] Figure 5 shows in the form of a block diagram an example of electrical architecture that can be implemented in all the antennas described

previously. In this example, the battery 40 supplies all the energy necessary for the various electrical loads of the antenna. The antenna is connected to the carrier by means of cable 14 which, in this example, only conveys information, for example by means of an optical fiber. In the antenna, the optical fiber is connected to an interface module 100 making it possible to transform the optical signals conveyed in the optical fiber into electrical signals. The interface module 100 is itself connected to an uplink interface module 102 providing the shaping of internal electrical signals to the antenna in the direction of the interface module 100. The interface module 100 is also connected to a downlink interface module 104 providing the shaping of electrical signals received from the interface module 100.

There are several arms 52 each carrying acoustic receivers 24. An Rx 112 reception module associated with each arm 52 makes it possible to shape the acoustic signals received from the acoustic receivers 24. The Rx 112 reception module is connected to the processor 106 to transmit the shaped signals to it. An actuator 114, controlled by the processor 106, allows the deployment of the arms 52. The actuator 114 can operate the arms 52 directly or

operate the opening and closing of the gripper 70.

The battery 40 comprises cells 116 which can accumulate or deliver electrical energy as well as a management module 118 ensuring the supervision of the state of charge of the cells 100. The management module 118 can also comprise the recharging means independent of the cable 14, represented here in the form of an induced winding allowing the recharging of the cells 116 without contact when the cable 14 is wound and the antenna is placed in the carrier.

In Figure 5, a high voltage direct current network 120 is connected to the battery 40. The network 120 mainly supplies the acoustic transmitters 22 via Tx converters 122 and if necessary through adapters 124 allowing the impedance matching with the acoustic transmitters 22. The antenna has for example as many Tx converters as there are rings 90. Other networks, in particular low voltage, can also be present in the antenna , in particular to power the printed circuit 108 and other electrical loads that do not require high voltage. In order not to overload FIG. 5, these other networks are not shown. The Tx 122 converters are only used for short periods of time and it is advantageous to pool their use with other loads. More precisely, the acoustic emissions only take place during the acoustic detection phase during which the winch 26 is stopped. Conversely, when the antenna descends or ascends under the action of the winch 26, there is neither transmission nor acoustic reception. It is therefore possible to use the Tx converters 122 outside the acoustic detection phase, in particular to supply the winch 26 and more precisely its electric motor 30.

The Tx converters 122 are for example inverters converting the direct voltage of the network 120 into alternating voltage either at the frequency of the acoustic waves that one wishes to emit in the water, or at a frequency compatible with the speed of rotation of the electric motor 30. An inverter is particularly well suited to generate a variable frequency making it possible to continuously vary the speed of the electric motor 30. The converters are for example controlled by a PWM pulse width modulator 126 controlling in particular the opening and closing of electronic switches belonging to the various Tx converters 122. The PWM pulse width modulator 126 can receive a command from a driver module 128.The command is for example an image of the alternating signal delivered either to the electric motor 30 or to the acoustic receivers 24.

[0051] The Tx 122 converters can be unidirectional. In other words, the Tx 122 converters only supply the loads assigned to them. Moreover, during the lowering of the antenna, the electric motor 30 can regenerate electrical energy which it is then necessary to dissipate, for example in an electrical resistor. Alternatively, it is possible to provide bidirectional Tx converters 122 making it possible to recharge the battery 40 when a regenerative load is connected to it, in particular the electric motor 30 during the descent. In addition to the possible recharging of the battery 40 by the electric motor 30 operating as a generator, it is useful to provide a resistor making it possible to dissipate the regenerated power when the maximum charge of the battery 40 is reached.

CLAIMS

1. Dipped sonar comprising an antenna (20; 50; 80) equipped with acoustic transmitters (22) and receivers (24), characterized in that it further comprises a motorized winch (26) comprising a reel (32) , an actuator (30) configured to rotate the reel (32) and a cable (14) wound on the reel (32), in that the winch (26) is disposed in the antenna (20), and in that that the cable (14) makes it possible to attach the antenna (20) to a carrier (10, 16) at a free end of the cable (14).

2. dipped sonar according to claim 1, characterized in that the antenna (50;

80) comprises deployable arms (52) on which the acoustic receivers (24) are arranged, the deployable arms (52) being articulated with respect to a housing (29) of the antenna (50) and a body (54; 82 , 84) movable in translation relative to the housing (29) along a main axis (28) of the cable (14), in that the arms (52) are articulated relative to the body (54; 82, 84), in that that in a first position of the body (54; 82, 84) in its translation relative to the housing (29), the arms (52) are folded against the housing (29) and in that in a second position of the body (54 ;

82, 84) in its translation relative to the housing (29), the arms (52) are deployed.

3. Dipped sonar according to one of the preceding claims, characterized in that the antenna (80) comprises several rings (90) each carrying acoustic emitters (22), a body (82, 84) movable in translation relative to the casing (29) along a main axis (28) of the cable (14), in that the rings (90) and the body (82, 84) are interconnected by means of extensible links (92), in that in a first position of the body (82, 84) in its translation relative to the housing (29), the rings (90) and the body (82, 84) are in contact with each other and in that in a second position of the body (82, 84) in its translation relative to the housing (29), the rings (90) and the body (82, 84) are spaced from each other.

4. dipped sonar according to one of claims 2 or 3, characterized in that the body (54; 82, 84) is provided with a clamp (70) configured to clamp the cable (14), allowing, in a position open of the clamp (70), the body (54; 82, 84) to occupy its first position and allowing, in a closed position of the clamp (70), the body (54; 82, 84) to occupy its second position.

5. Dipped sonar according to one of the preceding claims, characterized in that the antenna (20; 50; 80) comprises a battery (40) and recharging means

of the battery (118) not passing through the cable (14), the battery (40) making it possible to supply the acoustic transmitters (22) and the actuator (30).

6. Dipped sonar according to claim 5, characterized in that the antenna comprises at least one energy converter (122) making it possible to supply either the acoustic transmitters (22) or the actuator (30).

7. Dipped sonar according to claim 6, characterized in that the energy converter (122) is bidirectional allowing either the battery (40) to power the actuator (30) or the actuator (30) to recharge the battery (40).