Abstract: A bathythermograph buoy and an associated method of operation are provided to measure temperature and/or optionally other parameter(s) within an ocean or another body of water. A bathythermograph buoy includes a housing and one or more sensors carried by the housing and configured to repeatedly measure one or more respective parameters as the bathythermograph buoy descends. The bathythermograph buoy of one example also includes a memory carried by the housing and configured to store representations of the one or more respective parameters measured by the one or more sensors. The bathythermograph buoy further includes a buoyancy modification device configured to increase buoyancy of the bathythermograph buoy to permit the bathythermograph buoy to ascend.

Abstract: An example cantilever assembly includes a cantilever including an anchor configured to be coupled to a support, a tip, and an arm positioned between the anchor and the tip, a hollow conductive tube positioned at the tip of the cantilever, and a magnet suspended inside the hollow conductive tube with a first spring and a second spring. The first spring and the second spring are positioned at a first end and a second end of the hollow conductive tube respectively, and the magnet is positioned between the first spring and the second spring. The magnet is configured to move coaxially inside the hollow conductive tube as permitted by the first spring and the second spring, and the magnet suspended inside the hollow conductive tube operates as a tuned mass damper (TMD) to limit a resonant response of the cantilever assembly.

Abstract: Systems and methods are provided for aerostat deployable from sonobuoy launch container. One embodiment is an apparatus that includes a capsule configured to launch from an aircraft and float in seawater with one or more sonobuoys. The capsule includes a receiver configured to receive sonobuoy data from the one or more sonobuoys, a transmitter configured to transmit the sonobuoy data to the aircraft, a cable configured to power the transmitter via a battery, and a reaction chamber including a reactant and configured to generate a gas from the seawater mixing with the reactant. The capsule also includes an aerostat tethered to the capsule via the cable and configured to inflate with the gas produced by the reaction chamber, and to ascend above the capsule with the transmitter to increase a distance for transmitting the sonobuoy data to the aircraft.

Abstract: Systems, methods, and devices are disclosed herein for Doppler based position estimation. Systems may include an antenna configured to receive a radio frequency (RF) signal from an emitter, and configured to generate an output signal based on the received RF signal. Systems may also include a receiver configured to receive the output signal from the antenna. The receiver may include one or more processors configured to identify a plurality of initial conditions for a plurality of state variables associated with the emitter, obtain a measurement of the RF signal from the emitter and an estimate of an uncertainty associated with the measurement, and generate an output based, at least in part, on an updated estimate of the plurality of state variables, the output identifying a position, velocity, and carrier frequency of the emitter. Systems may also include a communications interface configured to communicatively couple the antenna with the receiver.

Abstract: A bathythermograph buoy and an associated method of operation are provided to measure temperature and/or optionally other parameter(s) within an ocean or another body of water. A bathythermograph buoy includes a housing and one or more sensors carried by the housing and configured to repeatedly measure one or more respective parameters as the bathythermograph buoy descends. The bathythermograph buoy of one example also includes a memory carried by the housing and configured to store representations of the one or more respective parameters measured by the one or more sensors. The bathythermograph buoy further includes a buoyancy modification device configured to increase buoyancy of the bathythermograph buoy to permit the bathythermograph buoy to ascend.

Abstract: An example cantilever assembly includes a cantilever including an anchor configured to be coupled to a support, a tip, and an arm positioned between the anchor and the tip, a hollow conductive tube positioned at the tip of the cantilever, and a magnet suspended inside the hollow conductive tube with a first spring and a second spring. The first spring and the second spring are positioned at a first end and a second end of the hollow conductive tube respectively, and the magnet is positioned between the first spring and the second spring. The magnet is configured to move coaxially inside the hollow conductive tube as permitted by the first spring and the second spring, and the magnet suspended inside the hollow conductive tube operates as a tuned mass damper (TMD) to limit a resonant response of the cantilever assembly.

Abstract: Systems and methods are provided for aerostat deployable from sonobuoy launch container. One embodiment is an apparatus that includes a capsule configured to launch from an aircraft and float in seawater with one or more sonobuoys. The capsule includes a receiver configured to receive sonobuoy data from the one or more sonobuoys, a transmitter configured to transmit the sonobuoy data to the aircraft, a cable configured to power the transmitter via a battery, and a reaction chamber including a reactant and configured to generate a gas from the seawater mixing with the reactant. The capsule also includes an aerostat tethered to the capsule via the cable and configured to inflate with the gas produced by the reaction chamber, and to ascend above the capsule with the transmitter to increase a distance for transmitting the sonobuoy data to the aircraft.

Abstract: Systems, methods, and devices are disclosed herein for Doppler based position estimation. Systems may include an antenna configured to receive a radio frequency (RF) signal from an emitter, and configured to generate an output signal based on the received RF signal. Systems may also include a receiver configured to receive the output signal from the antenna. The receiver may include one or more processors configured to identify a plurality of initial conditions for a plurality of state variables associated with the emitter, obtain a measurement of the RF signal from the emitter and an estimate of an uncertainty associated with the measurement, and generate an output based, at least in part, on an updated estimate of the plurality of state variables, the output identifying a position, velocity, and carrier frequency of the emitter. Systems may also include a communications interface configured to communicatively couple the antenna with the receiver.