A tracking beacon is provided that is trackable using image sensors. The beacon includes a housing with a lower portion and an upper portion. The upper portion include a light diffusing structure with protrusions to help scatter the emitted light in different directions. A light source is positioned within the housing, and electrical contacts are positioned on an external surface of the lower portion.

Circuits for controlling magnetic-based tracking systems are described. These systems may be used in virtual reality applications, for example to track in real-time the location of one or more body parts. The systems use a beacon emitting mutually orthogonal magnetic fields. On the receiver side, one or more sensors disposed on different parts of a body receive the magnetic fields. The beacon includes switching amplifiers for driving the magnetic field emitters. Being binary, these amplifiers may be controlled by binary signals. The circuits may exhibit a resonant frequency response, and may be operated off-resonance, thus providing for a better control of the magnetic fields amplitude. As a result, however, fluctuations in the envelop of the magnetic fields due to the presence of a beating tone may arise. These fluctuations may be shortened by gradually activating the drivers for the magnetic field emitters.

A method and system for detecting a position of an animal in laboratory conditions based on ultrasonic tracking is disclosed. The animal has an attached mobile device comprising an ultrasonic receiver. Ultrasonic signals emitted from ultrasonic emitters either have an envelope with a shape that is chosen with the first derivative restricted by condition |dE/dt|<A/T and/or with the second derivative restricted by condition |d.sup.2E/dt.sup.2|<A/T.sup.2, wherein E(t) is the envelope curve, t is time, A is the maximum amplitude of the ultrasonic signals and T is the period of the base frequency of the ultrasonic signals; or oscillations of voltage or current of ultrasonic emitters during signal transmission have envelopes described by a special function for amplitude of the oscillations. The mobile device receives an optical or radio synchronization signals from signal sources connected with the ultrasonic emitters. Analog or digital filters are used to separate ultrasonic signals from animal's vocalization. In some embodiments coordinates are obtained by using optical scanning sources with ultrasonic emitter placed at the axes of rotation of one or two emitted rotating planar scanning light beams. Tracking for multiple animals is disclosed.

An assembly is provided combining a low power light source, a distance measuring radio, an electrical storage and an adapter compatible with an existing socket for a light unit. The unique configuration of the assembly enables deployment of distance measuring radios in buildings, vehicles and outdoor venues without the need to install dedicated infrastructure such as electrical grid connections. A method is further disclosed of automatically determining the location of a newly installed assembly by first learning the locations of already installed neighboring assemblies, measuring the distances to such known assemblies, and using the measured distances to determine the location of the newly installed assembly.

A tracking beacon is provided that is trackable using image sensors. The beacon includes a housing with a lower portion and an upper portion. The upper portion include a light diffusing structure with protrusions to help scatter the emitted light in different directions. A light source is positioned within the housing, and electrical contacts are positioned on an external surface of the lower portion.

A tracking beacon is provided that is trackable using image sensors. The beacon includes a housing with a lower portion and an upper portion. The upper portion include a light diffusing structure with protrusions to help scatter the emitted light in different directions. A light source is positioned within the housing, and electrical contacts are positioned on an external surface of the lower portion.

An underwater communications network may include spaced apart nodes on a bottom of a body of water. The underwater communications network may also include fiber optic cabling connecting the spaced apart nodes. Each node may include a frame, a node short-range navigation device carried by the frame, and an unmanned underwater vehicle (UUV) carried by the frame after delivering a fiber optic cable along a navigation path from an adjacent node. The UUV may be configured to cooperate with the node short-range navigation device during an end portion of the navigation path adjacent the frame.

A system is configured to obtain locations of a mobile device (1) and obtain presence detection information. The locations are determined using visible light signals and dead reckoning information recorded at different moments. The presence detection information indicates presence detected using presence sensor devices (31, 32) at the different moments. The system is further configured to obtain sensor locations and sensor fields of view, determine sensor orientations based on the locations of the mobile device, the sensor locations and the presence detection information, and determine a sensor coverage area (61, 62), comprising gaps in the sensor coverage area, based on the sensor locations, the sensor orientations and the sensor fields of view. The system is also configured to determine one or more parameters for presence detection based on the gaps in the sensor coverage area and output the parameters or a presence detection result which has been determined using the parameters.

Obtaining a target location of a user associated with a body worn device (50) that receiving information related to a condition of user and communicates an indication of the condition to a server (12) over a network (24). The method including: providing a network (24) formed of a plurality of lighting units (42, 32) and a database (22) for maintaining information describing a geographic location of each of the plurality of lighting units, each lighting unit transmitting a unique identifier; providing the body worn device with a lighting unit identifier sensor (52), the sensor receiving lighting unit identifiers of at least one of the plurality of lighting units; the body worn device communicating the received lighting unit identifiers with the indication in a message to the server via the network; and the database providing a geographic location of the one or more lighting units, the geographic location corresponding to the target location of the body worn device.

Circuits for controlling magnetic-based tracking systems are described. These systems may be used in virtual reality applications, for example to track in real-time the location of one or more body parts. The systems use a beacon emitting mutually orthogonal magnetic fields. On the receiver side, one or more sensors disposed on different parts of a body receive the magnetic fields. The beacon includes switching amplifiers for driving the magnetic field emitters. Being binary, these amplifiers may be controlled by binary signals. The circuits may exhibit a resonant frequency response, and may be operated off-resonance, thus providing for a better control of the magnetic fields amplitude. As a result, however, fluctuations in the envelop of the magnetic fields due to the presence of a beating tone may arise. These fluctuations may be shortened by gradually activating the drivers for the magnetic field emitters.