Decoy Rounds For Counter Measures System

Abstract

This disclosure relates to decoy rounds for launching from launcher systems which may be installed aboard a ship or the like, or which may be of a portable type. The decoy rounds provide a protective cover for craft such as war ships, against homing devices operating upon infrared or microwave-reflected energy or against craft utilizing sound navigation and ranging systems. The decoy rounds contain one or more bundles of either RF chaff, infrared energy creating pellets, or bubble creating pellets, or any combination thereof, and are provided with a launch charge and a dispersion charge for each of the bundles of decoy material therein.

Parent Case Text

This application is a divisional application of U.S. Pat. application Ser. No. 389,525, filed Aug. 12, 1964, and assigned to the same assignee.

Description

This invention relates to countermeasures systems, and more particularly to a system for providing a protective cover for war ships against homing and/or fire control devices operating upon infrared or microwave-reflected energy.

It is well known that many missiles are capable of homing on objects which emit infrared or microwave-reflected energy. If there is more than one energy radiating object within the homing cone of the missile, the point it will target on will depend on the intensity, distance to, and distribution of the several energy sources. This invention is directed to a system for dispensing infrared and/or microwave-reflected energy by firing a projectile or a plurality thereof from ships or the like which carries the energy sources and dispenses the same at a predetermined point in time or position along its trajectory or path of travel whereby these additional energy sources confuse the sensor system of the incoming missile and divert it from its intended target.

Therefore, it is an object of this invention to provide a countermeasure system.

Another object of the invention is to provide a countermeasure system for providing a protection cover for craft against homing and/or fire control devices operating upon infrared or microwave-reflected energy.

Another object of the invention is to provide a countermeasure system including means for dispensing infrared and/or microwave-reflected energy sources for confusing the homing devices.

These and other objects of the invention will become readily apparent from the following description and accompanying drawings wherein:

FIG. 1 is a perspective view of a craft utilizing the invention;

FIG. 2 is a perspective view of the decoy launcher of the invention;

FIG. 3 is a view partially in cross-section of a decoy round of the invention;

FIG. 4 is a view partially in cross-section of decoy round for sonar applications; and

FIG. 5 is a block diagram illustrating the invention.

This invention broadly relates to a system for providing a protective cover for craft such as war ships against homing devices operating upon infrared on microwave-reflected energy. Specifically, the warship is provided with decoy launchers which fire a round containing chaff and infrared pellets into the area surrounding the vessel, the chaff being of three bands x, s, and c and being adapted to form an artificial cloud which can be intermittently illuminated by shipboard radar. The cover devices are operated from a countermeasure control console.

Referring now to the drawings, FIG. 1 shows a warship 10 incorporating a fast reaction fighting system (FRFS) which includes sensors, computers, launchers, and missiles for effectively conducting anti-air and anti-surface ship combat. A modern volume scanning radar indicated generally at 11 is employed as the primary input. Target information from the primary radar 11 is processed for display by a digital computer (not shown). Target tracks and predicted tracks as generated in the digital computer are used to analyze the battle situation. In addition to providing the information for data displays, the same track predictions from the digital computer are used to provide information for aiming target illuminators, for aiming a missile launcher 12, and for generating prelaunch instructions for the missile which may be of the Tartar guided missile class.

To maintain the fighting ability of the FRFS in a heavy countermeasures environment, a countermeasures/counter-countermeasures control center is included. All enemy countermeasures (ECM) information is collected and displayed at this control display console. The operator then has the option of selecting the optimum counter-countermeasures (CCM) mode for the equipment being jammed, or alternately, to establish countermeasures of his own to confuse the enemy or to cause the enemy to withdraw his countermeasure pressure.

An aggressive and resourceful enemy will present a countermeasure (CM) situation to the FRFS which varies from engagement to engagement over the full range of his technological capability. Any CM scheme he uses which fails will be rapidly supplanted by one which is different and therefore has a greater chance for success.

The CM/CCM portion of the FRFS is designed to allow a flexible reaction to changing enemy tactics and strategies. Information concerning the enemy's jamming and the general tactical situation is fed to a central point. Analysis of this information allows a rapid determination of the best strategy. A combination of multiple receivers, decoys, and RF jamming transmitters allows facilitation of the selected strategy.

The CM portion of the system is designed to deceive, confuse, and/or deny information to the enemy. The CCM portion of the system is designed to gain information the enemy is trying to conceal.

The CM operator has the option of trying to deceive, confuse or deny information to the enemy by the use of the following techniques:

1. Deception

a. Chaff and infrared decoys can be launched.

b. The decoys can be enhanced by RF illuminators.

c. Multiple target response can be transmittergenerated.

2. Confusion

a. Conical scan inversion responses can be transmitted.

b. Range gate-stealing or track-breaking modulated RF can be transmitted.

c. With consort ship cooperation, blinking of jammers of each type can be produced.

3. Denial

a. Selective, programmed or responsive barrage jamming can be provided.

b. Spot, multi-spot or enhanced multi-spot jamming can be provided.

c. Smoke generators for visual denial are available.

d. Many chaff decoys can be launched toward the enemy to screen and prevent radar penetration.

e. Directional antennas can be employed on the intership link (aimed by track information from central computer).

The CCM operator has a number of ways to gain information the enemy is trying to conceal. These methods can be grouped into those based on frequency diversity, geometry, burn-through, or the use of home-on-jamming.

1. Diversity

a. Radar receivers

b. Stabilized optical sight

2. Geometry

a. Directional antennas of known pattern on each radar receiver.

b. Two servo-driven parabolic dish antennas (port and starboard).

c. Angular information on jammers from consort ship allowing triangulation.

3. Burn-through

a. Long pulse burn-through mode on primary 3D radar.

b. Can use maximum power (flight time duty factor) from single illuminator.

4. Home-on-Jam

a. The Tartar missile's "Home-on-Jam" mode will allow destruction of X-band jamming targets within range.

This invention is directed primarily to the countermeasure (CM) system of the fast reaction fighting system (FRFS) and specifically to the deception techniques utilizing infrared and RF chaff decoys which can be enhanced by RF illuminators. Ship 10 is provided with a plurality of multicell mortar type decoy dispensers or launchers 13 (shown in detail in FIG. 2). As shown in FIG. 1, dispensers or launchers 13 are mounted starboard and port in the forward end of main superstructure 14 and on the outboard thereof (only the starboard outboard launcher being shown). Launchers 13 may also be positioned in the aft portion of ship 10. Each launcher is operatively connected into the firing circuit connectors and the intervalometer (not shown). Data as to number of rounds fired is automatically displayed on the CM control console launcher status panel (not shown). Fail safe and automatic protection for the magazine handling crew is provided.

Launcher or dispenser 13, as shown in FIG. 2, comprises a mounting base 15 and a disposable launcher portion 16, portion 16 being provided with a plurality of mortar-like cells 17. Each of cells 17 is adapted to fire decoy rounds 18 shown and described with respect to FIG. 3.

As shown in FIG. 3, decoy rounds 18 are combination chaff and infrared rounds, the chaff being radiant energy-reflecting metallic particles such as aluminum, for example, which are quickly and widely scattered so that an effective radar target is promptly obtained. Rounds 18 are self-contained mortar-type projectiles. Each round 18 carries two (2) C-, S-, and X-band chaff bundles 19, a bundle of infrared (sodium or potassium pellets) candles 20, a launch charge 21, three (3) expelling charges 22 for bundles 19 and 20, and necessary wiring all contained within a casing 23. A separator plate 24 is positioned between an expelling charge 22 and the adjacent decoy bundle; while a plate 25 separates the launch charge 21 from the wiring connections adjacent the aft separator plate 24. The decoy rounds 18 are electrically fired by the CM controller as individual rounds, in intervalometer timed automatic sequences, or as massive simultaneous launches where all fore, aft, port and starboard rounds are fired simultaneously. Each round is automatically fused at launch to fire the chaff and infrared bundles 19 and 20 at or near the apogee of the flight path or at a preset altitude. The individual expelling or powder charges between each bundle are fired to separate and deploy the payload. Each decoy round 18 produces a radar and infrared target similar to the launching ship 10.

As shown in FIG. 1, decoy rounds 18 having been fired from launchers 13 of ship 10 disintegrate by the explosion of charges 22 and disperse the chaff 19 and infrared candles 20 at a predetermined distance from the ship where the chaff spreads due to the air currents, and creates microwave or infrared-sensing targets thereby providing a deceptive countermeasure system against an impending attack.

Referring now to FIG. 4, an embodiment of a decoy round 18' is provided for applications above and beneath the water. The round 18' comprises a propellant charge 30 attached to a decoy cartridge casing 31. Casing 31 contains ballast material 32, a sub-surface load chamber 33, an above-surface load chamber 34, a delay fuse 35 interconnecting chambers 33 and 34, a fuze initiator 36, a delay fuze 37 interconnecting initiator 36 and chamber 34, an electric squib 38 operatively connected with initiator 36, a fuze 39 interconnecting propellant charge 30 with initiator 36, a fuze 40 interconnecting delay fuzes 35 and 37, and electric wiring 41 connected to squib 38. Wiring 41 is removably connected to electrical leads 42 which extend into casing 31 and which are connected with a battery 43 through a switch 44 and electronic apparatus 45. Sub-surface load chamber 33 includes a dispensing explosive charge 46 which is adapted to be fired by a fuze 47 connected with delay fuze 35, a pair of lithium hydroxide capsule containers 48, and a lithium powder container 49. The above-surface load chamber 34 includes a dispensing explosive charge 50 which is adapted to be fired by fuze 40, and a pair of lithium hydroxide capsule containers 51.

In operation, closing of switch 44 directs electrical energy from battery 43 through leads 42 and wires 41 to the electric squib 38 which activates fuze initiator 36 which ignites fuze 39 and delay fuze 37. Ignition of fuze 39 fires the propellant charge 30 which propells the round 18' from launcher or dispenser 13 into a predetermined trajectory. At a certain point in the trajectory of the round, delay fuze 37 ignites fuze 40 which in turn ignites the dispensing explosive charge 50 which disintegrates containers 51 and dispenses the lithium hydroxide capsules above the surface of the water. Ignition of fuze 40 also ignites delay fuze 35. The remainder of the round, namely, chamber 33 and ballast 32 enters the water while delay fuze 35 is burning. At a predetermined time after the chamber 33 enters the water delay fuze 35 ignites fuze 47 which in turn ignites the dispensing explosive charge 46 which disintegrates containers 48 and 49 and dispenses the lithium hydroxide capsules and the lithium powder under the surface of the water, thus generating bubbles in the water for sonar deception.

The control system of the invention as shown in FIG. 5 comprises a control center or console 60 which controls the operation of decoy dispenser or launcher 13 which, when activated, fires decoys 18 and/or 18' as described above. The radio frequency (RF) chaff 19 (see FIG. 1) dispensed by decoy round 18 can be intermittently illuminated by a shipboard traveling-wave tube broad band coherent receiver/transmitter (TWT) 61 having an antenna 62 mounted on superstructure 14 of ship 10. The RF energy being transmitted by the TWT 61 and antenna 62 corresponds discretely in frequency and phase with that being received from enemy radars, as presently described. The effect will be equivalent to multiple-blinking coherent jammers which will provide a curtain of confusion in front or surrounding the ship. The transmitted RF energy to the TWT 61 is modulated by modulator 63. Signals from an invader or target 64 are received by primary radar 11, processed through an RF receiver 65 to a plan position indicator (PPI) 66, whereby a visual indication of the invader 64 is observed at the control center or console 60.

In operation, when a signal of an approaching invader or target 64 is received by the primary radar 11, it is processed through RF receiver 65 to the plan position indicator 66 of control console 60. The controller or operator at the console 60 determines the type of countermeasures necessary and if the deceptive technique is to be utilized the controller activates the dispenser or launcher 13 to fire decoy rounds 18 and/or 18' as individual rounds in automatic sequence, or all fore, aft, port and starboard rounds fired simultaneously, or any combination thereof. Firing of decoys 18, for example, dispenses RF chaff bundles 19 and infrared bundles 20 (see FIG. 3) as shown in FIG. 1 which spread out due to wind currents, etc. On command from control console 60, the RF chaff 19 can be intermittently illuminated by the TWT 61 through antenna 62 at an energy level which corresponds discretely in frequency and phase with the signal received from invader or target 64. Thus as the plurality of dispersed RF chaff bundles 19 are illuminated the enemy sensor picks up blips from each illuminated bundle thereby confusing the homing system and diverting the invader from its initial course and proposed target. The infrared decoy bundles 20 similarly function to confuse an approaching invader utilizing a homing system sensitive to infrared energy.

While the invention has been described with respect to a ship incorporating the fast reaction fighting system, it may be utilized on any type of ship or the launcher and rounds may be of the "portable" type and thus utilized in a variety of applications. Also, the FIG. 4 embodiment may be of the same general configuration as the FIG. 3 embodiment. In addition, the rounds may contain only infrared, sonar, or microwave-reflecting decoys or any combination thereof.

It has thus been shown that this invention provides an effective and yet relatively simple and inexpensive countermeasure system for providing a protective cover for craft, such as war ships, against homing devices operating upon infrared or microwave-reflected energy. While the invention has been illustrated and described with respect to a war ship, it can be effectively used for any land, sea or air vehicle requiring protection from homing devices operating on infrared or microwave-reflected energy.

While particular embodiments have been illustrated and described, modifications thereof will be readily apparent to persons skilled in the art, and it is intended to cover in the appended claims all such modifications as come within the spirit and scope of the invention.

Claims

What I claim is:

1. A decoy round adapted to be fired from a launcher comprising: a launch charge, a plurality of RF chaff bundles, a bundle containing material capable of creating infrared energy, and a plurality of explosive charges for individually dispersing said bundles.

2. The decoy round defined in claim 1, wherein said launch charge, said plurality of RF chaff bundles, said bundle containing material capable of creating infrared energy, and said plurality of explosive charges are positioned longitudinally within a housing, said plurality of explosive charges being separated from one another by one of said bundles.

3. A decoy round for sonar confusion comprising: means for launching said round, means for dispensing a portion of said round above surface of the water, means for sinking the remainder of said round beneath the water surface, and means for dispensing the remainder of said round beneath the water surface, said round including means capable of creating a sonar signal relector.

4. The decoy round defined in claim 3, wherein said means for launching said round includes a propellant charge and a fuze means for igniting said charge; wherein said round dispensing means includes a pair of explosive charges and fuze means, said last mentioned fuze means includes a pair of delay fuzes and a pair of fuzes for igniting said pair of explosive charges, one of said delay fuzes interconnecting said explosive charge igniting fuzes, the other of said delay fuzes and said propellant charge igniting fuze means being operatively connected such that each are activated substantially simultaneously.

5. The decoy round defined in claim 3, wherein said material in each of said portions of said round includes at least an amount of lithium hydroxide, whereby contact of said lithium hydroxide with water generates bubbles.

6. The decoy round defined in claim 3, wherein said material in at least said portion of said round dispensed under water includes at least lithium powder.

7. A decoy round adapted to be fired from a launcher comprising: a launch charge, means for igniting said launch charge, dispersible decoy material, explosive material for dispersing said decoy material, fuse means for igniting said explosive material, and means for substantially simultaneously actuating said launch charge igniting means and said explosive material igniting fuse means.

8. The decoy round defined in claim 7, wherein said dispersible decoy material includes at least one bundle containing RF chaff.

9. The decoy round defined in claim 7, wherein said dispersible decoy material includes at least one bundle containing material capable of creating infrared energy.

10. The decoy round defined in claim 7, wherein said dispersible decoy material includes at least one bundle containing means capable of creating a sonar signal reflector.