An echo measuring apparatus has: a transmission signal forming unit for forming a transmission signal by a pseudo noise sequence signal; a transmitting unit for transmitting the transmission signal as an ultrasonic wave into the water; a receiving unit for receiving an echo of the ultrasonic wave; and a correlator for discriminating the echo corresponding to the transmission signal by executing a correlating process to the echo by the pseudo noise sequence signal and measuring a distance to a measurement target on the basis of a time difference between the transmission signal and the echo, wherein assuming that a velocity of a sound wave in the water is equal to Vu and the distance to the measurement target is equal to D, a period of the transmission signal includes a case where it is equal to or less than (2D/Vu).

A method uses an underwater vehicle travelling along an underwater surface projecting high frequency sound at the underwater surface to produce an image of the underwater surface with sufficient along track and cross track resolution to be able to identify cracks or other irregularities in the underwater surface.

An underwater vehicle provided with a sonar for detecting underwater objects, the sonar being a sonar whose angular coverage in elevation is comprised between 45 and 240 degrees, is oriented towards the surface when the underwater vehicle is in the detection phase of an underwater object and whose angular coverage in bearing is less than 10 degrees to obtain measurements in a plane, all the measurements of a plane being obtained in one emission/reception cycle, the sonar allowing the detection of underwater objects located at a depth less than that of the underwater vehicle.

Provided are an ultrasonic diagnostic apparatus that is capable of generating an image caused by fundamental components of ultrasonic echo signals and synthesizing the generated image with an image caused by harmonic components so that an image having both advantages of the images can be generated, and a method of controlling the ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus includes: a transmission beam generating unit that generates a plurality of sets of transmission beams by setting transmission beams which are transmitted in different transmission scan line positions and in which the sum of waveforms is 0, to one set; a reception beam generating unit that generates reception beams with respect to at least one reception scan line in consideration of transmission delay of the transmission beams in each of the transmission scan lines; a signal processing unit that extracts fundamental components and harmonic components from the reception beams, respectively; a synthesization unit that generates synthesized signals by synthesizing the fundamental components and the harmonic components according to a set synthesization ratio; and a display unit that displays a synthesized image including the synthesized signals.

Systems and methods are disclosed herein for a pressure tolerant energy system. The pressure tolerant energy system may comprise a pressure tolerant cavity and an energy system enclosed in the pressure tolerant cavity configured to provide electrical power to the vehicle. The energy system may include one or more battery cells and a pressure tolerant, programmable management circuit. The pressure tolerant cavity may be filled with an electrically-inert liquid, such as mineral oil. In some embodiments, the electrically-inert liquid may be kept at a positive pressure relative to a pressure external to the pressure tolerant cavity. The energy system may further comprise a pressure venting system configured to maintain the pressure inside the pressure tolerant cavity within a range of pressures. The pressure tolerant cavity may be sealed to prevent water ingress.

A coded imaging and multi-user communications systems using novel codes, algorithms to develop such codes, and technological implementations to use the codes for various types of systems involving multiple (or single) transmitters and multiple (or single) receivers of signals (which could include but are not limited to electromagnetic radiation, acoustic waves, other types of waves or data) as a function of time-or-space.

A system may be configured for implementing neural volumetric reconstruction for coherent synthetic aperture sonar. Exemplary systems include means for measuring underwater objects using high-resolution Synthetic aperture sonar (SAS) by coherently combining data from a moving array to form high-resolution imagery. Such a system may receive a waveform from the measurements of the underwater object and optimize the waveform for deconvolving via an iterative deconvolution optimization process applying an adaptable approach to waveform compression where performance is tuned via sparsity and smoothness parameters. Such a system may deconvolve the wave form using pulse deconvolution and use the deconvolved waveforms in an analysis-by-synthesis optimization operation with an implicit neural representation to yield higher resolution and superior volumetric reconstruction scene of the underwater object.

A synthetic aperture sonar (SAS) system utilizes a novel timing and pointing method to illuminate and process data from multiple receive channels over one or more elevation swaths. The system further utilizes cross-track interferometry to improve accuracy of three-dimensional mapping.

Systems and methods for adding buoyancy to an object are described herein. A buoyant material may be enclosed inside a flexible container, heated, and inserted into a free flooded cavity inside the object. The flexible container may then be formed to the shape of the cavity. After the flexible container is formed to the shape of the cavity, the flexible container may be cooled. The flexible container may hold a pre-determined amount of the syntactic material that provides a fixed amount of buoyancy. According to another aspect, systems and methods for packing a vehicle are described herein. In some embodiments, a buoyant material may be molded into the shape of a hull of a vehicle, and a plurality of cutouts may be extracted from the buoyant material which are specifically designed to incorporate one or more instruments.

Systems and methods are disclosed herein for a pressure tolerant energy system. The pressure tolerant energy system may comprise a pressure tolerant cavity and an energy system enclosed in the pressure tolerant cavity configured to provide electrical power to the vehicle. The energy system may include one or more battery cells and a pressure tolerant, programmable management circuit. The pressure tolerant cavity may be filled with an electrically-inert liquid, such as mineral oil. In some embodiments, the electrically-inert liquid may be kept at a positive pressure relative to a pressure external to the pressure tolerant cavity. The energy system may further comprise a pressure venting system configured to maintain the pressure inside the pressure tolerant cavity within a range of pressures. The pressure tolerant cavity may be sealed to prevent water ingress.