Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: Disclosed are systems comprising: a transmitter background; a receiver background; a plurality of transmitter units affixed on the transmitter background, each transmitting an encoded electromagnetic wave (EM), wherein the electromagnetic wave is transmitted as a wide beam; and a plurality of receiver units affixed on the receiver background, wherein each of the plurality of the transmitter units is in electromagnetic communication with at least one of the receiver units. Also disclosed are methods of identifying the presence of an object intersecting a spatial surface. Further, a housing for the system is disclosed.

Abstract: Disclosed are systems comprising: a transmitter background; a receiver background; a plurality of transmitter units affixed on the transmitter background, each transmitting an encoded electromagnetic wave (EM), wherein the electromagnetic wave is transmitted as a wide beam; and a plurality of receiver units affixed on the receiver background, wherein each of the plurality of the transmitter units is in electromagnetic communication with at least one of the receiver units. Also disclosed are methods of identifying the presence of an object intersecting a spatial surface. Further, a housing for the system is disclosed.

Abstract: Disclosed are garage door sensor systems and devices that include one or more transmitter sources configured to transmit an electromagnetic (EM) waveform and one or more receiver circuits configured to receive the electromagnetic waveform from the transmitter source. The receiver circuit is configured to determine an active duration of the received electromagnetic waveform in a predetermined detection time window. The receiver circuit is configured to send a blocked beam signal based on the determined active duration and the predetermined detection time window. The blocked beam signal indicates to the garage door motor assembly that an obstruction is in the signal path between the transmitter source and a receiver sensor of the receiver circuit.

Abstract: Disclosed are systems comprising: a transmitter background; a receiver background; a plurality of transmitter units affixed on the transmitter background, each transmitting an encoded electromagnetic wave (EM), wherein the electromagnetic wave is transmitted as a wide beam; and a plurality of receiver units affixed on the receiver background, wherein each of the plurality of the transmitter units is in electromagnetic communication with at least one of the receiver units. Also disclosed are methods of identifying the presence of an object intersecting a spatial surface. Further, a housing for the system is disclosed.

Abstract: An acoustic dual-frequency phased array system with common beam angles is disclosed. In one aspect, the system includes a planar array of transducer elements and a multiplexing circuit for selecting between a first state and a second state during either transmit operation, receive operation or both transmit and receive operation. The multiplexer is configured to connect transducer elements to a plurality of connections different between the first state and second state. The system is configured to transmit and receive beams at a first frequency when the multiplexer is in the first state and transmit and receive beams at a second frequency when the multiplexer is in the second state. The angle of the beams from vertical in the first and second state are substantially similar.

Abstract: An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

Abstract: An acoustic transducer and method of generating acoustic transmit and receive beams is disclosed. The system includes a plurality of transducer elements arranged to form an array, where the elements are electrically connected into groups which operate at the same electrical phase, where the phases of adjacent groups of elements differ by between about 50 and 70 degrees and a beamforming circuit where the transmit and receive signals are operated with appropriate phase shifts to maintain the between about 50 and 70 degrees phase difference between adjacent groups. The resulting transducer generates transmit and receive beams that are nominally inclined less than about 30 degrees from a planar normal axis of the array.

Abstract: Disclosed are systems comprising: a transmitter background; a receiver background; a plurality of transmitter units affixed on the transmitter background, each transmitting an encoded electromagnetic wave (EM), wherein the electromagnetic wave is transmitted as a wide beam; and a plurality of receiver units affixed on the receiver background, wherein each of the plurality of the transmitter units is in electromagnetic communication with at least one of the receiver units. Also disclosed are methods of identifying the presence of an object intersecting a spatial surface. Further, a housing for the system is disclosed.

Abstract: An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: An acoustic dual-frequency phased array system with common beam angles is disclosed. In one aspect, the system includes a planar array of transducer elements and a multiplexing circuit for selecting between a first state and a second state during either transmit operation, receive operation or both transmit and receive operation. The multiplexer is configured to connect transducer elements to a plurality of connections different between the first state and second state. The system is configured to transmit and receive beams at a first frequency when the multiplexer is in the first state and transmit and receive beams at a second frequency when the multiplexer is in the second state. The angle of the beams from vertical in the first and second state are substantially similar.

Abstract: Disclosed are systems comprising: a transmitter background; a receiver background; a plurality of transmitter units affixed on the transmitter background, each transmitting an encoded electromagnetic wave (EM), wherein the electromagnetic wave is transmitted as a wide beam; and a plurality of receiver units affixed on the receiver background, wherein each of the plurality of the transmitter units is in electromagnetic communication with at least one of the receiver units.

Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: An acoustic transducer and method of generating acoustic transmit and receive beams is disclosed. The system includes a plurality of transducer elements arranged to form an array, where the elements are electrically connected into groups which operate at the same electrical phase, where the phases of adjacent groups of elements differ by between about 50 and 70 degrees and a beamforming circuit where the transmit and receive signals are operated with appropriate phase shifts to maintain the between about 50 and 70 degrees phase difference between adjacent groups. The resulting transducer generates transmit and receive beams that are nominally inclined less than about 30 degrees from a planar normal axis of the array.

Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: An optical device capable of concentrating and spectrum splitting electromagnetic radiation for solar energy conversion systems. Two interfaces of the optical device, designed by ray tracing methods, focus the electromagnetic radiation by refraction and chromatic dispersion, such that focal areas of different wavelengths, relative to one another, are not parallel to electromagnetic radiation incident upon the optical device. Energy conversion devices, such as solar photovoltaic cells, may be placed at or near the focal areas to efficiently convert radiation of different wavelengths to other forms of energy. Interfaces may be flat or curved and may be composed of multiple discontinuous surfaces on one or both interfaces in one or two axes. Interfaces composed of multiple discontinuities may be designed such that there is no shading of electromagnetic radiation of selected wavelengths. The optical device may be composed of one material or multiple materials with different Abbe numbers.

Abstract: An optical device capable of concentrating and spectrum splitting electromagnetic radiation for solar energy conversion systems. Two interfaces of the optical device, designed by ray tracing methods, focus the electromagnetic radiation by refraction and chromatic dispersion, such that focal areas of different wavelengths, relative to one another, are not parallel to electromagnetic radiation incident upon the optical device. Energy conversion devices, such as solar photovoltaic cells, may be placed at or near the focal areas to efficiently convert radiation of different wavelengths to other forms of energy. Interfaces may be flat or curved and may be composed of multiple discontinuous surfaces on one or both interfaces in one or two axes. Interfaces composed of multiple discontinuities may be designed such that there is no shading of electromagnetic radiation of selected wavelengths. The optical device may be composed of one material or multiple materials with different Abbe numbers.