Abstract:
A standoff delivery system is responsive to GPS coordinate signals and in-flight GPS signals to deploy a torpedo at a remote location that avoids the limitations and hazards attendant conventional deployment by full size aircraft. A gliding rigid winged unmanned aircraft carries the torpedo to a desired remote location. A GPS receiver on the aircraft enters GPS coordinate signals representative of the remote location and receives GPS signals representative of the location of the unmanned aircraft. A control signal generator produces control signals in response to both of the GPS signals and feeds control signals to servos that displace control surfaces to pilot the unmanned aircraft. The torpedo is released and descends via parachute in response to GPS signals that are representative of at least the proximity of the remote location. This system provides for clandestine deployment of a torpedo without exposing manned aircraft to danger.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation in part of U.S. patent application entitled “Standoff Delivered Sonobuoy” by Robert Woodall et al., U.S. Patent and Trademark Office Ser. No. 09/137,874 filed Aug. 17, 1998 now U.S. Pat. No. 6,082,675 and incorporates all references and information thereof by reference herein. 
    
    
     STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to deployment of torpedoes. In particular, this invention relates to a method and system for remotely delivering torpedoes accurately and clandestinely with reduced exposure to hostile response. 
     Torpedoes are effective against shipping. Most navies have numerous attack torpedoes in inventory. These torpedoes use various sensors and data inputs to seek and engage enemy ships or submarines. Unless attack torpedoes are released from a mine, they are usually launched from surface, subsurface, and airborne platforms to engage and destroy targets. These deployments may work reasonably well under a variety of operational scenarios, but they cannot deliver a torpedo in an area that is strongly defended without placing the host air or sea platform at great risk. This is because torpedo-dispensing platforms usually need to perform their torpedo-dispensing mission well within the detection range of the target. Consequently, the target and other vessels may retaliate and hunt them down. In other words, the conventional deployment methods for torpedoes are observable, and the presence of the relatively large platform alerts others so that its activities are closely monitored and invite decisive countermeasures. 
     Launching torpedoes by relatively undetectable submarines is not without its disadvantages. Submarines are slow as compared to torpedo dispensing aircraft. If a submarine is to engage a target about 100 nautical miles from its position, it might take many hours to navigate the distance underwater. Thus, to ensure stealthy operation, a submarine&#39;s slow and careful progress will operationally limit it, especially if the operation is taking place through a hostile monitored region. Once a torpedo is launched, the submarine&#39;s location is likely to be revealed. Evasive maneuvering during the submarine&#39;s withdrawal to safer waters location may be needed to ensure survivability. This can take hours during which time the submarine is vulnerable to counter attack from surface, subsurface, and airborne platforms. Thus, airborne platforms may be more desirable to deliver torpedoes from safe and undetected standoff positions. Some aircraft can take less than an hour to deploy torpedoes and return to base without detection. However, if such aircraft are detected, they too are vulnerable to destruction. 
     Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for a means to remotely deploy torpedoes clandestinely with GPS accuracy that reduce risks and hazards. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to providing a method of and means for remotely deploying a torpedo to a remote area. Mounting a torpedo on a rigid winged unmanned aircraft and flying the torpedo to a remote location calls for generating control signals in the unmanned aircraft in response to entered GPS coordinate signals representative of the remote location and to received GPS signals representative of the location of the unmanned aircraft. Steering the unmanned aircraft to the remote location in response to the control signals allows releasing the torpedo from the flying unmanned aircraft in response to GPS signals that are representative of the proximity of the remote location. 
     An object of the invention is to provide a method and means for remotely deploying a torpedo with GPS accuracy. 
     Another object of the invention is to provide an unmanned aircraft deploying a torpedo to a remote location in response to GPS signals. 
     Another object of the invention is to provide method and means for remotely deploying a torpedo according to GPS coordinates and signals. 
     Another object of the invention is to provide method for deploying standoff delivered torpedoes that provides the capability of remotely launching torpedoes in defended areas without exposing friendly craft to detection and hostile action. 
     Another object of the invention is to provide for deployment of torpedoes from an unmanned gliding aircraft when conventional systems for deploying torpedoes are unavailable or could not perform such missions. 
     Another object of the invention is to provide a method to accurately deploy torpedoes using GPS signals and much closer to high-risk areas without exposing craft or personnel to risk. 
     Another object of the invention is to provide a method and system that provide for clandestine deployment of torpedoes. 
     Another object is to provide a system that allows torpedoes to be remotely emplaced many nautical miles from a point of aim. 
     Another object of this invention is to provide a method and means to deploy torpedoes in engagement areas that can be lethal for conventional aircraft deploying torpedoes in current fashion. 
     These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic top view of a guided wing releasably mounting a torpedo for its remote deployment 
     FIG. 2 depicts the deployment sequence. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1 of the drawings, system  100  deploys a torpedo  20  to a remote location, or site via a glider structure or guided wing  10  that functions as a rigid winged unmanned small aircraft. Guided wing  10  has a pair of pivotable wings  13  which are depicted as partially pivotally extended. These wings can be folded to lie alongside fuselage  11  during release from a launch platform, such as a conventional aircraft, or can be extended to be nearly perpendicular from fuselage  11  during gliding and deployment of torpedo  20  to the remote location where torpedo  20  may be guided by wire, active homing, and/or passive homing. 
     Guided wing  10  is released (launched) from the conventional aircraft or may be raised to heights for launching by a rocket or balloon. Guide wing  10  has an adaptor plate  22  joined to releasable band clamps  15  that are wrapped about case  20 ″ of an elongate cylindrically-shaped torpedo  20 . Adaptor plate  22  houses an explosive charge  23  that may aid separation of guided wing  10  from torpedo  20  when torpedo  20  is to be released from guided wing  10 . Guided wing  10  may have separation lugs (not shown) engaging wing  10  and torpedo  20  to hold them together during flight instead of clamps  15 . Adaptor plate  22  also houses parachute  24  that is deployed after this separation, or release to slow the fall of torpedo  20  into water. Releasable clamps  15  are actuated by servo controls  15   a  to selectively engage and disengage case  20 ″ of torpedo  20 . Clamps  15  hold torpedo  20  in place for the duration of a flight by launch platform to a desired remote location. Then, clamps  15  are released, or disengaged, separation charge  23  is exploded, and torpedo  20  is slowed in its descent by parachute  24  to the ocean. 
     Some of the components of guided wing  10  are typical of many proven designs developed over the years for a variety of radio controlled model aircraft and drone aircraft. Like nearly all of this variety of aircraft, guided wing  10  has one type or another radio receiver  10   a  connected to an antenna  10   b  that receives remotely originating radio control signals  10   a′.  Receiver  10   a  is coupled to provide appropriate signals for suitable servo controls  10   c  that are each joined to displace control surfaces  12 . Control surfaces  12  cooperate to provide substantially the same composite functions as ailerons, elevators, and rudders of conventional model aircraft, and are displaced in accordance with remote control signals  10   a′  received on antenna  10   b  to pilot guided wing  10 . This basic radio control capability is kept in this system  100  of this invention to launch and divert guided wing  10  or return it to the launch platform at any time after launch. 
     Guided wing  10  also includes GPS system  30  that has GPS receiver  35  coupled to GPS antenna  36 . GPS receiver  35  is typical of many commercially available units that are preprogrammed or preset with coordinate signals to “home in” on a remote location after the GPS coordinates of the remote location (or destination way point) are entered into it. Once the desired GPS coordinate signals are entered, the well-known combination of GPS receiver  35  and antenna  36  sense GPS signals  30   a′  from several satellites  30   a,  see FIG. 2, to provide signals representative of the location of guided wing  10  and corrective signals to correctly orient guided wing  10  toward the preprogrammed remote site. 
     The GPS coordinate signals and corrective signals are fed from GPS receiver  35  to signal generator module  40 . Signal generator module  40  generates appropriate control signals based on the preset coordinate signals and corrective signals and feeds these control signals to servo controls  10   c  and  15   a  to displace control surfaces  12  and clamps  15 . 
     Components and interconnections for signal generation module  40  and servo controls  10   c  and  15   a  are well known in the art. A considerable number of off-the-shelf units have been available for radio controlled model aircraft and boats for quite some time. In addition, boating and aircraft enthusiasts have used numerous navigational aids, such as auto pilots, which interface with GPS signals to steer a given course to a preset destination. Therefore, having this disclosure before him, one skilled in the art to which this invention pertains is free to choose and appropriately interconnect suitable components for the GPS responsive system of this invention from a number of freely available model and full-scale marine and aircraft systems. 
     A satisfactory design for a guided wing  10  might be the guided wing kit marketed by Leigh Aerosystems Corp. of Carlsbad, Calif., under the trademark LONGSHOT™. This guided wing kit has control circuitry and mechanisms responsive to entered GPS coordinate signals and remotely transmitted GPS signals from NAVSTAR satellites and has been mounted on heavy pieces of ordnance. 
     Wings  13  are pivoted out from fuselage  11  after they have been released from a mother aircraft. The extended wings provide sufficient lift to carry the ordnance on a gliding decent to a predetermined target. Other glide wing designs that may be used are disclosed in U.S. Pat. Nos. 4,453,426 and 4,842,218. Still other guided wing kits such as those under the trademark CONDOR of Leigh Aerosystems, or the military designation JDAM may be selected to deploy torpedoes  20  that may include torpedoes guided by wire, active homing, and/or passive homing and known under the as MK-46, MK-48, or MK-50 of the U.S. Navy. 
     A designer is free to select an appropriate design for guided wing  10 ; however, it must have the strength and lift capabilities to carry and fly torpedo  20  with its interconnected parachute  24  about 50 or more nautical miles downrange to a designated remote location, or site. At this location or at least the proximity of the remote location, guided wing  10  releases torpedo  20  and, after a preset period has elapsed, parachute  24  slows its decent sufficiently to assure damage-free entry into the water. Torpedo  20  can search regions of the ocean, such as in or near harbors or shipping lanes, without exposing those that deployed it to danger or adverse publicity. Because of the small size, low noise and reduced radar and IR signatures of guided wing  10 , this deployment of torpedo  20  may be clandestine. 
     Referring also to FIG. 2, system  100  is depicted during its operational deployment sequence. Before takeoff of the deploying conventional aircraft, guided wing  10 , torpedo  20 , and parachute  24  of system  100  are mounted on a bomb rack via rings  14 . Torpedo  20  may be attached in pairs or singularly with dummy ballast on the opposite wing of the launching aircraft. Any torpedo  20  suitable for the task may be selected such as a MK-46, MK-48, or MK-50 torpedo. Also, at this time and/or during flight, the GPS aim point coordinates for deployment of torpedo  20  are entered into GPS system  30 . The aircraft flies to an appropriate altitude, 30,000 ft., for example, and GPS system  30  acquires GPS signals  30   a′  from NAVSTAR satellites  30   a.  When guided wing  10  and torpedo  20  are within range of the remote target location, they are released AA from the bomb rack of the aircraft which returns to base. This range may be about 50 nautical miles that guided wing  10  glides. Wings  13  unfold BB and GPS receiver  35  steers guided wing  10  toward the target location in accordance with the previously entered GPS coordinate data, and GPS signals acquired en route from NAVSTAR satellites  30   a  bring about course corrections via servo manipulations of control surfaces on wings  13 . 
     Guided wing  10  thereby steers torpedo  20  to an area approximately one nautical mile from the desired location and, optionally, may angle to a steep terminal descent to the aim point. When guided wing  10  and torpedo  20  reach within 2000 feet of the target area, guided wing  10  is jettisoned, or separated CC by separation of bands  15  and/or detonation of explosive charge  23  to deploy DD parachute  24  to slow the impact of torpedo  20  so that it is not damaged by entry in the water. Wing  10  falls away and torpedo  20  descends slowly to a damage free landing FF in the sea near the original GPS aim point (or within an area considered to be within an acceptable proximity of a desired location). 
     After entry in the water of torpedo  20  and at a depth of about 10 feet, a pressure switch and/or water sensor close so that an attached battery (not shown) fires a squib-and-separation charge (schematically shown as  24   a,    24   b,  and  24   c,  respectively) to free parachute  24  from torpedo  20 . Closing of pressure switch  24   a  and firing of separation charge  24   c  initiates the main battery power, seeker logic, and fuel propulsion systems of torpedo  20 . This sequence ensures safety to the aircraft during deployment as well as to allow torpedo  20  to initiate at the proper time within the proper environment. Thereafter, torpedo  20  begins to actively acquire the targeted enemy vessel using active and passive sonar techniques, as designed. Upon determination by logic on torpedo  20  that it has acquired a valid target, torpedo  20  travels through the water a predetermined distance from the targeted vessel and detonates its main warhead at the target. An adversary may expend resources to begin a counter attack, but no platform will be detected since the deploying aircraft is far from the scene. 
     System  100  of this invention allows conventional aircraft to be used to deploy torpedo  20  from a safe standoff position, with pin point GPS accuracy. This allows the aircraft and its crew to stay out of harms way during deployment of torpedo  20 . System  100  allows for a stealthy emplacement of torpedo  20  so that an adversary may be misled into believing an attack is coming from a nearby platform, and consequently, critical resources may be expended chasing after something that does not exist. System  100  also may be used to deceive and create the illusion that a number of nearby platforms for dispensing torpedoes  20  are operating in vast areas. This illusion may help conceal the actual locations of the real submarines. In addition, system  100  can be used to neutralize targets in water that is shallower than where a submarine can safely operate. 
     In accordance with this invention, a GPS responsive system is provided for safe delivery and emplacement of torpedoes  20  in engagement areas that would otherwise be dangerous or lethal for conventional aircraft if they were to deploy torpedoes in current fashion. This system also clandestinely deploys and activates torpedoes  20  where they are needed at considerable ranges. This invention has the capability to remotely deliver torpedo  20  from a standoff range and can perform this task when conventional aircraft and helicopters are unavailable for such missions. This invention utilizes superior GPS technology to emplace torpedoes much closer to high risk areas without putting craft or personnel at risk. 
     The disclosed components and method of deployment as disclosed herein all contribute to the novel features of this invention. Torpedoes can be more reliably and effectively utilized since others are not alerted to their emplacement in a contested region of the ocean. In addition, many of the hazards are avoided that characterize the conventional deployment of torpedoes by full scale aircraft and ships. 
     Furthermore, having this disclosure in mind, one skilled in the art to which this invention pertains will select and assemble suitable components for fabrication of differently configured guided wings  10  from among a wide variety of materials and components available in the art to satisfactorily deploy different torpedoes  20  as disclosed herein. Therefore, the disclosed arrangement is not to be construed as limiting, but rather, is intended to be demonstrative of this inventive concept. 
     It should be readily understood that many modifications and variations of the present invention are possible within the purview of the claimed invention. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.