An interferometric synthetic aperture acoustic imager is disclosed. Specifically, an acoustic imaging system includes an acoustic transmitter, an acoustic receiver array, a signal processing system, a navigation data system, and a meteorological data system. The acoustic transmitter and the acoustic receiver array are mounted on transceiver array. The navigation data system includes a Position and Orientation System for Land Vehicles system which receives data from two Global Positioning System antennas, an inertial measurement unit, and a wheel encoder mounted on a vehicle wheel. The system also includes meteorological data system that records temperature, relative humidity, and barometric pressure. The meteorological data may be used to adjust the received acoustic data based on atmospheric conditions.

An acoustic imaging system includes a controller. The controller may be configured to receive a signal from a microphone and reverberation channel data, update latent variables, latent labels, a source amplitude, and a phase estimation based on an optimization of the signal and reverberation channel data to obtain updated latent variables, updated latent labels, an updated source amplitude, and an updated phase estimation, generate, via a conditional generative adversarial network (cGAN) of the updated latent variables and the updated latent labels, an acoustic source map tuned via the updated source amplitude and the updated phase estimation, optimize the acoustic source map, and output the optimized acoustic source map.

Techniques for determining coherency between composite images having phase and amplitude components are disclosed. The coherency can be determined based on the amplitude components of the images, by providing first and second amplitude images indicative of amplitude values of pixels of a respective first and second composite images, applying to each of the first and second amplitude images a first directional derivative operator and a second directional derivative operator, thereby generating for each of the amplitude images respective first directional derivative image and second directional derivative image thereof, and generating a first coherency map based at least on the directional derivative images of the first and second amplitude images. The first coherency map is indicative of decorrelation between the first and second composite images.

An apparatus for artificial intelligence (AI) bathymetry is disclosed. The apparatus includes a sonic unit attached to a boat, the sonic unit configured to generate a plurality of metric data as a function of a plurality of ultrasonic pulses and a plurality of return pulses. An image processing module is configured to generate a bathymetric image as a function of the plurality of metric data, identify, as a function of the bathymetric image, an underwater landmark, and register the bathymetric image to a map location as a function of the underwater landmark. A communication module is configured to transmit the registered bathymetric image to at least a remote device. An autonomous navigation module is configured to determine a heading for the boat as a function of a path datum and command boat control to navigate the boat as a function of the heading.

Techniques are provided for implementing an end-fire synthetic aperture sonar system. A methodology implementing the techniques according to an embodiment includes generating a plurality of matched-filtered signals (pings) based on correlations of a transmitted sonar signal with a plurality of reflected or scattered returns of the transmitted signal received from a hydrophone, the reflected or scattered returns associated with a plurality of locations of the hydrophone relative to a location of a transmitter. The method further includes generating a coarse estimate of the locations of the hydrophone based on incoherent cross correlations of the pings, and generating a refined estimate of the locations of the hydrophone based on the coarse estimate and further based on coherent cross correlations of the pings. The method further includes performing delay-and-sum beamforming to combine the pings, the beamforming employing time delays based on the estimated locations of the hydrophone.

Ranging systems operate based on the transmission and receipt of pseudorandom sequences. Pseudorandom sequences may be generated and assigned to specific transmitters, which may operate simultaneously to transmit signals including the pseudorandom sequences. A receiver may be programmed to recognize the specific pseudorandom sequences within data captured by the receiver, and to associate the pseudorandom sequences with the transmitters that transmitted them. Upon identifying the pseudorandom sequences, the receiver or one or more associated components may calculate times of flight of signals transmitted by the respective transmitters. Such times of flight may be used to calculate distances to one or more objects from which the signals were reflected.

An apparatus for artificial intelligence (AI) bathymetry is disclosed. The apparatus includes a sonic unit attached to a boat, the sonic unit configured to generate a plurality of metric data as a function of a plurality of ultrasonic pulses and a plurality of return pulses. An image processing module is configured to generate a bathymetric image as a function of the plurality of metric data, identify, as a function of the bathymetric image, an underwater landmark, and register the bathymetric image to a map location as a function of the underwater landmark. A communication module is configured to transmit the registered bathymetric image to at least a computing device. An autonomous navigation module is configured to determine a heading for the boat as a function of a path datum and command boat control to navigate the boat as a function of the heading.

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.

Methods and apparatus for inspecting an underwater vehicle. In embodiments, a system receives a SAR image for at least a portion of an exterior surface of an underwater vehicle and performs CCD processing to compare a baseline SAS image for the underwater vehicle with the received SAR image of the underwater vehicle to generate a CCD output corresponding to a measure of similarity of the baseline SAS image and the received SAS image. The system determines whether there was tampering of the underwater vehicle based on the measure of similarity.

A method of determining at least part of the structure of an object, the method comprising the steps of providing at least one wideband acoustic signal transmission and reception device, the at least one wideband acoustic signal transmission and reception device being capable of transmitting and receiving one or more wideband acoustic signals, using the at least one wideband acoustic signal transmission and reception device to transmit at least one wideband acoustic signal towards at least a portion of the object, using the at least one wideband acoustic signal transmission and reception device to receive at least one wideband acoustic signal from the object, using the received at least one wideband acoustic signal from the object to create at least one acoustic data set, and analysing the at least one acoustic data set to determine the at least part of the structure of the object.