Abstract: A method for determining position of an aircraft with reference to a location on the ground includes transmitting an acoustic signal from a position on the aircraft to an array of spaced apart acoustic sensors proximate the location. The method includes at least one of (i) determining a time difference of arrival of the acoustic signal between each of the acoustic sensors and a reference acoustic sensor and (ii) determining an arrival time of the acoustic signal at each of the spaced apart acoustic sensors. The position of the aircraft is determined from the time differences of arrival and/or the arrival times.

Abstract: A system for imaging rock formations while drilling a wellbore includes a drill collar and a plurality of acoustic emitting transducers mounted in the drill collar at angularly spaced apart locations and oriented to emit acoustic energy at least one of laterally away from the drill collar and longitudinally away from the drill collar. A plurality of arrays of acoustic transducers arranged is longitudinally along the drill collar and angularly spaced apart from each other. Each transducer in the plurality of arrays is oriented normal to a longitudinal axis of the collar. Angular spacing between adjacent arrays is selected to provide lateral beam steered receiving response having a selected main lobe width and side lobe response for a plurality of rock formation acoustic velocities. A controller selectively actuates the emitting acoustic transducers at selected times.

Abstract: A helicopter position location system includes a receiver located substantially in a center of an array of receivers. A first array of receivers is located in a selected pattern separated from the center receiver by a first distance. Selected receivers in the first array are spaced apart from each other by at most one half wavelength of a base frequency of a locator signal transmitted from a helicopter. A second array of receivers is located in a selected pattern by a second distance larger than the first distance.

Abstract: A method for determining position and orientation of a rotating wing aircraft (e.g. helicopter) with respect to a ground station includes transmitting an electromagnetic signal from the aircraft. The signal includes a plurality of electromagnetic signals, each signal having a different selected frequency. The signal is detected at an array of sensors disposed on the ground surface in a selected pattern. The array includes at least one reference sensor and at least three spaced apart time difference determination sensors. A difference in arrival time of the signals between the reference sensor and each of the time difference determination sensors is determined and a spatial position of the aircraft is determined from the time differences.

Abstract: A system of determining a position of a mobile device within a surveillance volume includes a phase difference array comprising a spatially diverse array of N sensors for detecting RF signals from the mobile device and acquiring phase difference data from the RF signals, N being greater than 4. The system includes a processor for processing the phase difference data and determining the position of the mobile device from the phase difference data.

Abstract: An acoustic camera includes an acoustic transmitter disposed at one longitudinal end of a housing. The transmitter has a convex radiating surface. A diameter of the transmitter is about four times a wavelength of acoustic energy emitted by the transmitter. A plurality of acoustic receivers is disposed at spaced locations in a pattern extending laterally from the housing. A signal processor is in signal communication with the acoustic receivers. The signal processor is configured to cause the acoustic receivers to be sensitive along steered beams. The signal processor is configured to cause an end of the steered beams to move through a selected pattern within a beam width of the acoustic energy emitted by the acoustic transmitter. The signal processor is configured to operate a visual display device to generate a visual representation corresponding to acoustic energy detected by the acoustic receivers. A visual display device is in signal communication with the signal processor.

Abstract: A method for determining a position of a wireless electronic device within a volume includes detecting a signal transmitted by the wireless device during two-way communication to and from a first known position within the volume. The method further includes detecting the signal from at least three additional known positions within the volume, where the at least three additional known positions are spatially independent of each other. The method further includes determining a phase difference between the signal detected at the first position and the signal detected at each of the at least three additional positions, determining the position of the wireless electronic device using the phase differences, and at least one of displaying and storing the position of the wireless electronic device.

Abstract: A method for determining position of a mobile electronic device includes emitting an acoustic pulse from the position of the mobile electronic device. The acoustic pulse is detected at a known position at three spaced apart locations along each of at least two lines extending in different directions. The range and phase difference of the acoustic pulse between each of the detecting locations is determined. A relative position of the device with respect to the known position is obtained from the range and phase differences.