This invention relates to a system to emulate underwater mines. More particularly, the system of this invention provides high frequency acoustic responses to more thoroughly emulate acoustic sensor capabilities of some underwater mines.
Ships and other marine craft that ply the waterways radiate acoustic signals that are characteristic of their design, speed, on board machinery, etc. A specific composition of the acoustic signals is relied on in some mines to selectively initiate detonation when such signals are detected within a predetermined proximity. It is, therefore, of interest to be able to determine if such compositions of acoustic signals are being emitted in sufficient strength to trigger some mines.
A contemporary system for detecting, analyzing, and providing information regarding the compositions of such acoustic signals is limited in bandwidth. Consequently, it is not capable of emulating high frequency acoustic mines since its hardware is limited to 10 kHz and is not capable of receiving acoustic signals between 20 to 40 kHz. In addition, unlike some threat mines, it is also not capable of comparing acoustic signals from an omni-directional sensor and a directional sensor in this frequency range. These limitations have greatly reduced its ability to emulate mines that are responsive to higher frequencies.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for an effective means to extend the acoustic frequency response of an underwater system that senses remotely originating acoustic signals, collects acoustic data, and emulates mines.
An object of the invention is to provide an acoustic float system to extend the frequency response of an exercise mine system.
Another object is to provide an acoustic system extending acoustic frequency response to permit emulation of mines having extended frequency responses.
Another object is to provide an acoustic system for an exercise mine system creating a mine-fire capability that is a function of omni-directional and directional sensor outputs.
Another object is to provide an acoustic system having an inclinometer for measuring tilt attributed to ambient currents to aid in mine fire analyses.
Another object is to provide an acoustic system to extend the range of frequency response and account for inclination attributed to currents.
Another object is to provide an acoustic system being readily capable of being modified to emulate omni-directional and directional acoustic responses of different mines.
These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.
Accordingly, the invention extends the high-frequency response of a mine emulation system. A watertight housing has a first acoustic sensor extending through a cover portion to provide an omni-directional response to higher frequency acoustic signals impinging through ambient water. A second acoustic sensor extends through the cover portion of the housing adjacent to the first acoustic sensor. The second acoustic sensor provides a directional response to the higher frequency acoustic signals. Processing circuits in the housing receive signals from the first and second acoustic sensors and generate signals representative of the higher frequency omni-directional response and the directional response. A cable extends to a mine emulation system to feed the representative signals thereto for additional processing of the higher frequency responses.