A system for three-dimensional animal tracking in laboratory conditions is proposed. A mobile device that has one infrared and one ultrasonic sensor, equipped with memory and/or radio transmitter, is attached to a moving creature. One compact stationary box is placed in the vicinity; it emits a pre-determined sequence of short infrared pulses, short ultrasonic signals and two planar, radially emitted light beams that move through the area of interest with constant angular speed in two orthogonal directions. The mobile device receives two angular coordinates in the form of two time intervals between an infrared pulse and the next two orthogonal planar beam receptions, and it receives one linear coordinate in the form of the time interval between an infrared pulse and the next ultrasonic signal reception, taking into account the speed of sound in the air. The ultrasonic emitter is driven by a pulse-width modulated signal to make it undetectable by animals.

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.

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.

Systems and methods of transmitting location data based on wireless communication activity can include a location transmitting device having a sensor communicatively coupled to a low-power transmitter. The transmitter (e.g., a Bluetooth transmitter) can transmit location data from which an electronic device can derive its location. The sensor can be a sensor configured to detect wireless data transmissions (e.g., cellular data transmissions). In one example, the transmitter can transmit location data in response to the sensor detecting data transmissions of an electronic device. The transmitter can remain in an idle, standby, or otherwise low-power state until the sensor detects data transmissions of an electronic device. In response, the transmitter can transmit data which can be received by the electronic device. The electronic device can then derive the electronic device's location from the data transmitted by the transmitter.

A method for determining the location of a frequency receiver device with respect to at least two frequency originator devices, each of a current location, the method including synchronizing a clock of the frequency receiver device with a clock of one of the at least two frequency originator devices; receiving by the frequency receiver device, a message including an identification code configured for identifying one of the at least two frequency originator devices and obtaining a broadcast time and a current location of the one of the at least two frequency originator devices by looking up a table correlating the at least two frequency originator devices and their respective broadcast times and current locations; calculating a time of flight of the message by calculating the difference between a receive time at which the message is received by the frequency receiver device and the broadcast time.

A method for determining the location of a frequency receiver device with respect to at least two frequency originator devices, each of a current location, the method including synchronizing a clock of the frequency receiver device with a clock of one of the at least two frequency originator devices; receiving by the frequency receiver device, a message including an identification code configured for identifying one of the at least two frequency originator devices and obtaining a broadcast time and a current location of the one of the at least two frequency originator devices by looking up a table correlating the at least two frequency originator devices and their respective broadcast times and current locations; calculating a time of flight of the message by calculating the difference between a receive time at which the message is received by the frequency receiver device and the broadcast time.

Some embodiments are directed to a system for locating an object furnished with a tag in a predetermined space. The tag is interrogatable remotely by an RFID reader. According to the invention, a zone of sound is created with an ultrasound generator. A sound wave of frequency f1f2 is present in this zone. The tag is equipped with an acoustic sensor able to sense the signals of frequency f1-f2 and this acoustic sensor is designed together with the tag to modify the content or the level of the RFID tag response signal when the acoustic sensor receives a signal of frequency f1-f2. The RFID reader is then able to locate the object in the zone of sound when it receives the modified response signal from the RFID tag or when it no longer receives any response signal from the RFID tag.

Some embodiments are directed to a system for locating an object furnished with a tag in a predetermined space. The tag is interrogatable remotely by an RFID reader. According to the invention, a zone of sound is created with an ultrasound generator. A sound wave of frequency f1f2 is present in this zone. The tag is equipped with an acoustic sensor able to sense the signals of frequency f1-f2 and this acoustic sensor is designed together with the tag to modify the content or the level of the RFID tag response signal when the acoustic sensor receives a signal of frequency f1-f2. The RFID reader is then able to locate the object in the zone of sound when it receives the modified response signal from the RFID tag or when it no longer receives any response signal from the RFID tag.

A method for determining the location of a frequency receiver device with respect to at least two frequency originator devices, each of a current location, the method including synchronizing a clock of the frequency receiver device with a clock of one of the at least two frequency originator devices; receiving by the frequency receiver device, a message including an identification code configured for identifying one of the at least two frequency originator devices and obtaining a broadcast time and a current location of the one of the at least two frequency originator devices by looking up a table correlating the at least two frequency originator devices and their respective broadcast times and current locations; calculating a time of flight of the message by calculating the difference between a receive time at which the message is received by the frequency receiver device and the broadcast time.