Apparatus for displaying information associated with a wireless location node via a user interface based upon electromagnetic radiation received from a radio target area. More specifically, the present invention relates to methods and systems for receiving electromagnetic radiation received from a radio target area, and presenting digital content in a user interactive interface.

An apparatus and method for measuring a swimmer's speed and conveying the speed to the swimmer in real time includes a plurality of ultrasonic beacons each having a transducer configured to emit ultrasonic signals in a pool or other body of water within which the swimmer is swimming. A wearable, waterproof, ultrasonic receiver worn by the swimmer, receives the ultrasonic signals and generates corresponding signal data. The receiver's microcontroller captures and uses the signal data to calculate the swimmer's position and speed in real time, and conveys this information to a wearable, waterproof, user interface device worn by the swimmer, the user interface device including a near-eye display disposed on the swimmer's googles.

An ultrawide band two-way ranging based positioning system includes a number of active tags each having a position, and a number of beacons configured for location of a position of a tag of the plurality of active tags. The active tags and the beacons are synchronized continuously to a common time base.

A method for registering a location of a device with a floor plan of an indoor space determines a portion of the floor plan specifying a coarse location of the device using strength of WiFi signals received from at least three access points (APs). The location of each AP is registered with the floor plan. The method determines at least one distance between the device and at least one object registered with the floor plan using a time-of-flight of at least one acoustic signal and registers the location of the device within the portion of the floor plan at the distance from the object.

An acoustic underwater navigation system is disclosed. For instance, an underwater receiver determines its position using signals broadcast from an array of acoustic transmitters located near the surface. The position of the array is measured using global positioning system (GPS) technology and the transmitters collectively produce an acoustic signal in which the position and attitude of the array and the GPS time of transmission are encoded. An underwater receiver which is synchronized with the GPS time uses the transmitted position and attitude of the array and the transmission time information to calculate its position.

An acoustic underwater navigation system is disclosed. For instance, an underwater receiver determines its position using signals broadcast from an array of acoustic transmitters located near the surface. The position of the array is measured using global positioning system (GPS) technology and the transmitters collectively produce an acoustic signal in which the position and attitude of the array and the GPS time of transmission are encoded. An underwater receiver which is synchronized with the GPS time uses the transmitted position and attitude of the array and the transmission time information to calculate its position.

Disclosed is a positioning system using sound waves. The system provides the current location of a user carrying a dedicated terminal or any portable equipment possessing a microphone and a speaker in real time by using sound waves propagating in slow speed in various indoor spaces such as shopping malls, museums, and art galleries where GPS signals are not received.

Disclosed is a positioning system using sound waves. The system provides the current location of a user carrying a dedicated terminal or any portable equipment possessing a microphone and a speaker in real time by using sound waves propagating in slow speed in various indoor spaces such as shopping malls, museums, and art galleries where GPS signals are not received.

Music-based positioning (MP) provides positioning service only sporadically. To continuously provide positioning service, the present invention discloses music-based positioning aided by dead reckoning (MP-DR). At each signature burst (i.e., a highly unique short musical segment suitable for positioning), sounds of a music piece or a human speech are used for positioning. Between signature bursts, dead reckoning (DR) is used.

In general, this disclosure describes location techniques for a mobile device. A mobile device may request permission from a server device to perform a ranging operation. Responsive to receiving an indication of allowance, the mobile device may output a first data packet via a radio signal, which is received by a beacon device that activates an ultrasonic transponder upon receipt of the first data packet. The mobile device then outputs a second data packet via an ultrasonic pulse. The beacon device receives the ultrasonic pulse and outputs a third data packet via a second radio signal that includes information identifying the beacon device. The mobile device calculates a time difference between outputting the ultrasonic pulse and receiving the second radio signal and determines its location based on the third data packet and the time difference.