SYSTEM FOR ALTERNATIVELY OR CONCOMITANTLY MINE HUNTING AND MINESWEEPING Field Of Invention The present invention relates to a single system that combines mine hunting or minesweeping of underwater mines.

Background Of The Invention Heretofore, clearing a body of water from mines utilized separate systems for mine hunting (detection) and minesweeping.

Using separate mine hunting/minesweeping systems requires a substantial amount of time to install, display, operate and retrieve each system, thus limiting tactical mobility time on- station and increasing operational costs. For example, minesweeping has been carried out in the past with mission specific systems, such as the MK-105, a hydrofoil vehicle towed by a helicopter. A more complete description of the MK- 105 minesweeping system appears at Page 387 of Jane's Underwater Warfare Systems, Eleventh Edition 1999-2000, which description is incorporated by reference herein. In the instance of mine hunting, the AN/AQS-14 and AN/AQS-20 systems have been used, these systems performing only the mission of mine hunting. A more complete description of the AN/AQS-14 and AN/AQS-20 mine hunting systems appear at page 343 of the above-identified Jane's volume, which description is incorporated by reference herein. In recent military planning for mine hunting and minesweeping, there has been an emphasis on non-manned operations utilizing relatively small host

platforms, such as for example, Unmanned Surface Vehicles (USVs). Having separate USVs for each of the mine hunting and minesweeping missions results in the expenditure of excessive amounts of time for each of the mine hunting/minesweeping operations.

Various prior art mine hunting and minesweeping systems, wherein the system employs either, but not both, a mine hunting system or a minesweeping system are described in United States Patents Nos. 4,019, 453 ; 4,220, 108 and 4,562, 789.

Summary Of The Invention The present invention combines in a single system, a towed body, for example, the mine hunting and minesweeping functions. The single system results in a maximizing of on- station time for each operation and minimizes the manning requirements to install, launch, operate and retrieve the mine hunting and minesweeping sensors, and yet performs both the mine hunting and the minesweeping missions. For example, the system wherein a single towed body utilizes the Shallow Water Influence Minesweep System (SWIMS), incorporated by reference herein, and described at page 388 of the above-identified Jane's volume, a minesweeping system, integrated with a side scan sonar (mine hunting system) on the exterior of said towed body.

The single system hunt/sweep may employ other sweep and hunt systems. For example, the minesweep system may be a small light-weight open-loop sweeping system that has the ability to efficiently produce large magnetic and acoustic

influence fields capable of sweeping substantial areas. Such a system is described and claimed in United States Patent No.

6,286, 431 ('431), the disclosure of which patent is incorporated by reference herein. In particular, reference is made to the'431 patent commencing at Column 1, Summary Of The Invention and extending to the end of the specification for a description of a suitable open loop magnetic minesweeping system. A further open loop magnetic minesweeping system, wherein the cable towing the body 10 bearing one of the electrodes is described in pending U. S. Patent Application Serial No. 09/855,290, filed May 15, 2001, said pending application being incorporated by reference herein. In particular, reference is made to U. S. Serial No. 09/855,290 application commencing at page 1, Summary Of The Invention and extending to the end of the specification for a description of a further suitable open loop magnetic minesweeping system.

In addition to the sonar mine hunting system, electro- optical sensors such as LIDAR and highly sensitive magnetic anomaly sensors to detect (hunt) the mines may be utilized.

The towed body is controlled by an operator, which may be located in a remote location, many miles away, or co-located with the hunt/sweep systems, depending on the host tow platform and tactical requirements. The operator may switch between mine hunting and minesweeping or use both systems simultaneously, depending on mission needs.

The supporting electronics used to control the SONAR transducers may be housed in a water tight compartment located within the towed body. Signals may be sent from the water

tight compartment through an electro-mechanical-optical tow cable to the command and control console.

During a typical mission, the multi-mission towed body is installed on the host platform, which platform could be an airborne platform such as a manned or unmanned flight vehicle, e. g. , a helicopter or a surface vehicle, e. g. , an eleven meter Rigid Hull Inflatable Boat (RHIB).

In the instance of the RHIB, also referred to as an Unmanned Surface Vehicle (USV), the USV would be lowered into the water from a larger mother ship. An operator aboard the mother ship would remotely operate the USV and direct it to the area of operation. Once on station, the USV performs mine hunting or minesweeping operations, depending on environmental conditions and tactical requirements.

Where mine hunting is to be first carried out, the operator would command the deployment of the towed body via the USV's launch and retrieval system. After the towed body is payed out the desired distance, the hunting sensor, SONAR, for example, is energized and commences the mine hunting aspect of the mission. After completion of the mine hunting aspect, the mission switches to the minesweeping or clearance phase, the SONAR is de-energized and the minesweeping system is activated or energized. After completion of the minesweeping in the area, a command is issued to return the towed body to the USV and, subsequently, the USV with the towed body aboard is returned to the mother ship.

Alternatively, the minesweeping/mine hunting missions may be reversed or carried out simultaneously.

Other features and advantages of the present invention will be apparent from the following description, drawings and claims.

Brief Description Of The Drawings Figure 1 is a perspective view of a towed body of the subject invention schematically illustrating a mine hunting system employing a side scan sonar array and a minesweeping system employing dipole magnetic and acoustic signature technology.

Figure 2 is a perspective view of a USV having a towed body of the invention carried thereon and schematically illustrating components of the mine hunting/minesweeping combination.

Detailed Description Of Embodiments Referring to Figure 1, a towed body, generally designated as 10, is illustrated, the towed body being generally shaped in a torpedo-like streamlined fashion for smooth, fast and stable passage through water. Body 10, when towed, may be submerged and includes rear hydrodynamic fins 12 and possibly forwardly disposed hydrodynamic wings 14 to control the orientation, depth and direction of the towed body. A tow cable 15 may be connected at one end to a connector mechanism 17 and at the other end to a winch mechanism (not shown) on the towing platform (for example, on a towing helicopter or USV). The mechanisms for connecting the tow cable to the towed body 10 and the towing platform are well understood and

known to those skilled in the art and do not form a part of this invention. Also the towing platform will have means to cradle and carry the towed body 10 when not in mine hunting/minesweeping use ; all as known to those skilled in the art.

Further in Figure 1, there is stowed on the body 10 a magnetic influence signature system shown schematically at cut-out 18 for minesweeping such as described in the aforementioned U. S. Pat. No. 6,286, 431 and pending application Serial No. 09/855,290.

Additionally illustrated in Figure 1 is an electrodynamic acoustic device 20 that may take various well-known forms such as an electrodynamic moving coil transducer. One or more transducers may be located in towed body 10. Accordingly, towed body 10 provides complimentary magnetic and acoustic influence signatures for minesweeping. In Figure 1 there is also schematically shown at cut-out 22 a side scan SONAR transducer array.

In Figure 2, the USV, generally designated as 24, has a fuel supply 6 at midship, a minesweeping and mine hunting electronics control unit 28, a data link processor 30, an electric power generating source 32. Rearwardly, is disposed a winch 34 connected to a towed body 10 incorporating the mine hunting and minesweeping sensing equipment, the towed body shown nesting in a cradle 36.

Combining the hunt and sweep sensors in a single towed body results in the creation of a system that is capable of performing multiple functions with the same spatial

constraints as any one of the single mission systems. More importantly, the military will save precious time by not having to deploy, operate and retrieve multiple components.

The resulting savings in time could be as significant as 6-8 hours per mission. Prior to the subject invention, a mine hunting system would be installed on the host platform. Time to install the equipment is established to be 3-6 hours. The length of the actual mission would be dependent on the tactical situation. After the hunt mission was completed, the host platform would have to return to the mother ship (which could take a significant amount of time depending on stand-off distance). The hunt system would have to be removed, taking another 3-6 hours. When the hunt system was fully removed, the sweep system would have to be installed taking another 3-6 hours to complete the installation phase. Add to that the transit time required to get back out to the operational area, and clearly, by combining the two systems the invention eliminates a tremendous amount of non-mission time. The single towed body system will result in a much lower life cycle cost than two separate systems that require separate maintenance, training and logistics. In addition, by combining the two systems into one system, the benefit in space and storage requirements can be significant, especially when the systems are embarked on naval combatants, where space is always at a premium.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention without departing from the spirit and scope of the invention. The present embodiments, therefore, are to be considered as illustrative and not restrictive.