Abstract: A submersible vehicle for use in a body of liquid includes a vehicle body, a pair of fins coupled to the vehicle body on-opposed sides thereof, and a dihedral angle control system. The dihedral angle control is system operative to vary a fin dihedral angle of each of the fins.

Abstract: An unmanned submersible vehicle for use in a body of liquid having a top surface and in air overlying the top surface includes a hull, an integral antenna, and an antenna positioning system. The hull has first and second opposed ends. The hull includes a first hull portion adjacent the first end and a second hull portion adjacent the second end. The antenna is disposed within the first hull portion and/or is mounted on the first hull portion. The antenna positioning system is configured to reorient the hull from a transit position to a signal position.

Abstract: A payload delivery system for protecting and delivering a payload submerged in a submersion medium includes a containment system. The containment system includes a container and a dehiscing system. The container includes a pressure-resistant shell defining a sealed containment chamber. The dehiscing system is operative to dehisce the shell to open the containment chamber to the submersion medium responsive to a prescribed event and/or a prescribed environmental condition.

Abstract: A payload delivery unit for protecting and delivering a payload submerged in a submersion medium comprises a container including a pressure resistant shell and a resilient seal device. The shell defines a containment chamber and includes first and second shell members having opposed first and second sealing faces, respectively. The seal device engages and is interposed between the first and second sealing faces.

Abstract: A submersible vehicle for use in a body of liquid includes a vehicle body, a pair of fins coupled to the vehicle body on opposed sides thereof, and a dihedral angle control system. The dihedral angle control is system operative to vary a fin dihedral angle of each of the fins.

Abstract: A payload delivery system for protecting and delivering a payload submerged in a submersion medium includes a containment system. The containment system includes a container and a dehiscing system. The container includes a pressure-resistant shell defining a sealed containment chamber. The dehiscing system is operative to dehisce the shell to open the containment chamber to the submersion medium responsive to a prescribed event and/or a prescribed environmental condition.

Abstract: A payload delivery system for protecting and delivering a payload submerged in a submersion medium includes a containment system. The containment system includes a container and a dehiscing system. The container includes a pressure-resistant shell defining a sealed containment chamber. The dehiscing system is operative to dehisce the shell to open the containment chamber to the submersion medium responsive to a prescribed event and/or a prescribed environmental condition.

Abstract: A system for sound cancellation includes a source microphone for detecting sound and a speaker for broadcasting a canceling sound with respect to a cancellation location. A computational module is in communication with the source microphone and the speaker. The computational module is configured to receive a signal from the source microphone, identify a cancellation signal using a predetermined adaptive filtering function responsive to acoustics of the cancellation location, and transmit a cancellation signal to the speaker.

Abstract: A payload delivery unit for protecting and delivering a payload submerged in a submersion medium comprises a container including a pressure resistant shell and a resilient seal device. The shell defines a containment chamber and includes first and second shell members having opposed first and second sealing faces, respectively. The seal device engages and is interposed between the first and second sealing faces.

Abstract: A submersible vehicle for use in a body of liquid includes a vehicle body, a pair of fins coupled to the vehicle body on opposed sides thereof, and a dihedral angle control system. The dihedral angle control is system operative to vary a fin dihedral angle of each of the fins.

Abstract: A water submersible communications device for use on a body of water includes a housing and a communications module. The housing has a geometric centroid. The housing is submersible in and floatable on the body of water. The communications module is mounted on and/or in the housing. A center of buoyancy of the communications device is located substantially at the geometric centroid of the housing.

Abstract: An unmanned underwater vehicle for use in water and with at least one acoustic signal source includes a vehicle body, a steering mechanism to direct the vehicle body through the water, a propulsion device to force the vehicle body through the water, and an adaptive Doppler guidance and control (ADGC) system. The ADGC system is configured to receive acoustic signals from the at least one acoustic signal source and to control the steering mechanism using changes in at least one frequency component of the received acoustic signals caused by Doppler shifts.

Abstract: A submersible electronics device for use in a body of water and a substratum floor below the body of water includes a submersible housing, an operational electronics system, and a mobility system. The operational electronics system is mounted in and/or on the housing. The operational electronics system is adapted to communicate with another device and/or to sense at least one of a physical signal and an environmental parameter. The mobility system is selectively operable to fluidize the substratum, vibrate the housing, and/or adjust a buoyancy of the submersible electronics device to selectively move the housing into the substratum to at least partially bury the housing in the substratum and/or to selectively move the housing out of the substratum to at least partially unbury the housing from the substratum.

Abstract: An unmanned underwater vehicle for use in water and with at least one acoustic signal source includes a vehicle body, a steering mechanism to direct the vehicle body through the water, a propulsion device to force the vehicle body through the water, and an adaptive Doppler guidance and control (ADGC) system. The ADGC system is configured to receive acoustic signals from the at least one acoustic signal source and to control the steering mechanism using changes in at least one frequency component of the received acoustic signals caused by Doppler shifts.

Abstract: Methods for generating a directional sound environment include providing a headgear unit having a plurality of microphones thereon. A sound signal is detected from the plurality of microphones. A transfer function is applied to the sound signal to provide a transformed sound signal, and the transformed sound signal provides an approximation of free field hearing sound at a subject's ear inside the headgear unit.

Abstract: A submersible electronics device for use in a body of water and a substratum floor below the body of water includes a submersible housing, an operational electronics system, and a mobility system. The operational electronics system is mounted in and/or on the housing. The operational electronics system is adapted to communicate with another device and/or to sense at least one of a physical signal and an environmental parameter. The mobility system is selectively operable to fluidize the substratum, vibrate the housing, and/or adjust a buoyancy of the submersible electronics device to selectively move the housing into the substratum to at least partially bury the housing in the substratum and/or to selectively move the housing out of the substratum to at least partially unbury the housing from the substratum.

Abstract: A water submersible communications device for use on a body of water includes a housing and a communications module. The housing has a geometric centroid. The housing is submersible in and floatable on the body of water. The communications module is mounted on and/or in the housing. A center of buoyancy of the communications device is located substantially at the geometric centroid of the housing.

Abstract: A method of clearing a surface of an object contaminated with a polar material includes the steps of: providing an object having a surface with a plurality of spaced apart electrodes, the electrodes being connected with a voltage source and capable of sustaining a time-varying charge; inducing a first electric field on the plurality of electrodes of a magnitude and for a duration to induce drops of the polar material to take a first dimensional aspect; and inducing a second electric field on the plurality of electrodes of a magnitude and for a duration to induce the drops of the polar material to take a second dimensional aspect. With this method, surfaces such as the head window of a periscope can be cleaned/cleared of contaminants without requiring a manual cleaning and without the use of problematic coatings.

Abstract: A system for providing connectivity in an underwater environment includes a linking system, a target and a linking member. The linking system includes a first base and an unmanned, submersible mobile unit. The target is remote from the first base. The linking member is connected to one of the first base and the target. The mobile unit is operative to autonomously convey the linking member through the underwater environment from the first base to the target and/or from the target to the first base to interconnect the first base and the target via the linking member. According to some embodiments, the linking member is a flexible connecting line.

Abstract: Devices for navigating in a fluid medium having a solid boundary include a vehicle body and a fin attached to the vehicle body. The fin is configured to oscillate relative to the body such that interaction between the fin and the fluid medium produces propulsive forces that propel the vehicle body in a desired direction in the fluid medium. The fin is also configured to rotate relative to the body along a transverse axis such that engagement between the fin and the solid boundary propels the vehicle body in a desired direction on the solid boundary.