A practically implementable robust direction-of-arrival (DoA) estimation approach that is resistant to localization errors due to mobility, multipath reflections, impulsive noise, and multiple-access interference. As part of the disclosed invention the inventors consider infrastructure-less 3D localization of autonomous underwater vehicles (AUVs) with no GPS assistance and no availability of global clock synchronization. The proposed method can be extended to challenging communication environments and applied for the localization of assets/objects in space, underground, intrabody, underwater and other complex, challenging, congested and sometimes contested environments. Each AUV leverages known-location beacon signals to self-localize and can simultaneously report its sensor data and measurement location. The approach uses two known location beacon nodes, where the beacons are single-hydrophone acoustic nodes that are deployed at known locations and transmit time-domain coded signals in a spread-spectrum fashion.

A system, apparatus, method and computer program product determine the location of a receiver, such as one or more sensors, carried by a device, e.g., a robot. In a method, an audio signal is received in response to a predetermined audio signal provided by at least two audio source devices. For the audio signal that is received from a respective audio source device, the method estimates a first impulse response between the respective audio source device and the receiver. For the first impulse response estimated between each respective audio source device of the at least two audio source devices and the receiver, the method removes one or more reflections from the first impulse response to create direct path information. The method also includes determining a location of the receiver based at least in part upon the direct path information.

A system, apparatus, method and computer program product determine the location of a receiver, such as one or more sensors, carried by a device, e.g., a robot. In a method, an audio signal is received in response to a predetermined audio signal provided by at least two audio source devices. For the audio signal that is received from a respective audio source device, the method estimates a first impulse response between the respective audio source device and the receiver. For the first impulse response estimated between each respective audio source device of the at least two audio source devices and the receiver, the method removes one or more reflections from the first impulse response to create direct path information. The method also includes determining a location of the receiver based at least in part upon the direct path information.

Methods, apparatus, systems and articles of manufacture are disclosed to improve detection of audio signatures. An example apparatus includes at least one memory, instructions in the apparatus, and processor circuitry to execute the instructions to: determine a first time difference of arrival for a first audio sensor of a meter and a second audio sensor of the meter based on a first audio recording from the first audio sensor and a second audio recording from the second audio sensor; determine a second time difference of arrival for the first audio sensor and a third audio sensor of the meter based on the first audio recording and a third audio recording from the third audio sensor; determine a match by comparing the first time difference of arrival to i) a first virtual source time difference of arrival and ii) a second virtual source time difference of arrival; in response to determining that the first time difference of arrival matches the first virtual source time difference of arrival, identify a first virtual source location as the location of a media presentation device presenting media; and remove the second audio recording to reduce a computational burden on the processor.

Methods, apparatus, systems and articles of manufacture are disclosed to improve detection of audio signatures. An example apparatus includes at least one memory, instructions in the apparatus, and processor circuitry to execute the instructions to: determine a first time difference of arrival for a first audio sensor of a meter and a second audio sensor of the meter based on a first audio recording from the first audio sensor and a second audio recording from the second audio sensor; determine a second time difference of arrival for the first audio sensor and a third audio sensor of the meter based on the first audio recording and a third audio recording from the third audio sensor; determine a match by comparing the first time difference of arrival to i) a first virtual source time difference of arrival and ii) a second virtual source time difference of arrival; in response to determining that the first time difference of arrival matches the first virtual source time difference of arrival, identify a first virtual source location as the location of a media presentation device presenting media; and remove the second audio recording to reduce a computational burden on the processor.

Methods, apparatus, systems and articles of manufacture are disclosed to improve detection of audio signatures. An example apparatus includes a TDOA determiner to determine a first time difference of arrival for a first audio sensor of a meter and a second audio sensor of the meter, and a second time difference of arrival for the first audio sensor and a third audio sensor of the meter, a TDOA matcher to determine a match by comparing the first time difference of arrival to a first virtual source time difference of arrival and a second virtual source time difference of arrival, responsive to determining that the first time difference of arrival matches the first virtual source time difference of arrival, identify a first virtual source location as the location of a media presentation device, and remove an audio recording of the second audio sensor to reduce a computational burden on the processor.

Methods, apparatus, systems and articles of manufacture are disclosed to improve detection of audio signatures. An example apparatus includes a TDOA determiner to determine a first time difference of arrival for a first audio sensor of a meter and a second audio sensor of the meter, and a second time difference of arrival for the first audio sensor and a third audio sensor of the meter, a TDOA matcher to determine a match by comparing the first time difference of arrival to a first virtual source time difference of arrival and a second virtual source time difference of arrival, responsive to determining that the first time difference of arrival matches the first virtual source time difference of arrival, identify a first virtual source location as the location of a media presentation device, and remove an audio recording of the second audio sensor to reduce a computational burden on the processor.

An underwater remote locator device for tracking and positioning an object of the present disclosure can include a remote transducer system, abase transducer system, and a navigation module. The remote transducer system can be coupled to an object desired to be tracked. The remote transducer system can include a power source, processing means, acoustic receiver, and an acoustic transmitter. The acoustic transmitter can be configured to transmit a first acoustic wave in one or more directions. The base transducer system can include a processing means, a first base transducer having a first acoustic receiver, a second base transducer having a second acoustic receiver, and a third base transducer having a third acoustic receiver. Each acoustic receiver can be configured to receive said first acoustic wave from the remote transducer system.

An underwater remote locator device for tracking and positioning an object of the present disclosure can include a remote transducer system, abase transducer system, and a navigation module. The remote transducer system can be coupled to an object desired to be tracked. The remote transducer system can include a power source, processing means, acoustic receiver, and an acoustic transmitter. The acoustic transmitter can be configured to transmit a first acoustic wave in one or more directions. The base transducer system can include a processing means, a first base transducer having a first acoustic receiver, a second base transducer having a second acoustic receiver, and a third base transducer having a third acoustic receiver. Each acoustic receiver can be configured to receive said first acoustic wave from the remote transducer system.

The present invention relates to a laser rangefinder having common optical path comprising a housing assembly, a control and display assembly mounted in the housing assembly, a mounting device mounted in the housing assembly, an imaging module mounted on the mounting device and a laser module movably mounted on the mounting device longitudinally next to the imaging module, the laser module being electrically connected with the control and display assembly, the laser module comprising a laser emitting apparatus, a laser receiving apparatus and a reference point indicating apparatus, wherein a light path of the laser emitting apparatus and a light path of the laser receiving apparatus are configured to be independent to a light path of the reference point indicating apparatus, an optical axis of light path of the laser emitting apparatus shooting at the target object and an optical axis of the reference point indicating apparatus are collinear.