A method and a system for generating a plurality of ranging sound signals for positioning a mobile device are provided. The method includes: each of a plurality of ranging signal generating devices, which are connected to an audio signal cable and are located at different positions in an area, generating a ranging sound signal based on a synchronization signal transmitted on the audio signal cable, whereby location of the mobile device within the area can be obtained based on records of the ranging sound signals made by the mobile device. Accordingly, a plurality of speakers connected in series are able to be controlled to reproduce ranging sound signals for positioning a mobile device.

A sensor positioning device includes an inter-sensor distance measurement jig that measures a distance between two sensors, and is a reference when setting the distance between the two sensors to a target distance, and reference-setting jigs of sensor height position, each including a weight and a weight suspension member, a lengthwise direction of which is in a vertical direction when the weight is suspended, and each performing setting of a distance which is a total of a vertical direction dimension of the weight, a length of the weight suspension member, and a distance from an upper end of the weight suspension member to the sensor such that the distance coincides with a target height of the sensor, when the weight is in contact with a reference surface, in a state where the weight is attached to a sensor holding jig by the weight suspension member.

A system and methods for estimating the location of a mobile device are disclosed. In accordance with one embodiment, a mobile device located within a first corridor of a building receives (1) a first wireless electromagnetic signal and a first ultrasound signal from a first beacon located in the first corridor, (2) a second wireless electromagnetic signal and a second ultrasound signal from a second beacon located in the first corridor, and (3) a third wireless electromagnetic signal from a third beacon located in a second corridor of the building. The first wireless electromagnetic signal, the first ultrasound signal, the second wireless electromagnetic signal, and the second ultrasound signal are used to estimate a location of the mobile device.

An underwater celestial navigation beacon configured to provide position information is disclosed. The underwater celestial navigation beacon can include a data store configured to store an astronomical model of the moon. The underwater celestial navigation beacon can include an inertial measurement unit (IMU) operable to capture IMU data that includes three-axis acceleration data and three-axis rate gyroscopic data. The underwater celestial navigation beacon can include a controller. The controller can determine a latitude of the underwater celestial navigation beacon using the three-axis rate gyroscopic data. The controller can determine a longitude of the underwater celestial navigation beacon based on a gravitational pull of the moon, using the three-axis acceleration data and the astronomical model of the moon. The controller can determine the position information for the underwater celestial navigation beacon based on the latitude and longitude.

A system and methods are disclosed for synchronizing two or more groups of base stations in a wireless location system. In one embodiment, a first wireless base station belonging to a first group of wireless base stations transmits a first RF beacon for synchronizing the first group of wireless base stations and a second RF beacon that is used to synchronize a second group of wireless base stations. Wireless base stations in the first and second groups transmit respective non-RF (e.g., infrared, ultrasound, etc.) beacons that can be used to locate a portable tag.

A system and methods for estimating the location of a mobile device are disclosed. In accordance with one embodiment, a mobile device receives a wireless electromagnetic signal and an ultrasound signal from a first beacon during a first occurrence of a time slot. The mobile device further receives a wireless electromagnetic signal and an ultrasound signal from a second beacon during a second occurrence of the time slot, where the ultrasound signals from the first and second beacons have non-overlapping areas of coverage. The electromagnetic and ultrasound signals from the first beacon are used to estimate a first location of the mobile device, and the electromagnetic and ultrasound signals from the second beacon are used to estimate a second location of the mobile device.

Deployable navigation beacons can be deployed from a vehicle, such as an unmanned aerial vehicle (UAV), in an event of a loss of position or orientation of the vehicle. After deployment of the navigation beacons, the vehicle may detect locations of the navigation beacon, which may define a surface that may include surface features. The vehicle may then perform control operations based on the resolved locations. For example, UAV may maneuver to land proximate to the navigation beacons after resolving locations of the navigation beacons as a continuous surface. The navigation beacons may output a visual signal (e.g., a light), a auditory signal (e.g., a sound), and/or a radio signal. In some embodiments, each navigation beacon may include a different or unique signal.

The invention relates to hydroacoustics and more specifically to hydroacoustic devices comprising, disposed in a single housing, a converter of liquid-medium oscillations and electrical signals, capable of receiving and/or transmitting hydroacoustic signals, the converter being disposed on a board which is connected to a switch cable for providing power and transmitting electrical signals, and may be used as a receiver and/or transmitter of hydroacoustic signals in water. According to the invention, the housing of the to hydroacoustic device is formed by the outer surfaces of the converter and board, and by a protective material which coats all of said surfaces, said material allowing for a transmission of hydroacoustic oscillations and being capable of transitioning from a highly-elastic or viscous-flow state to a solid state. The achieved technical result consists in simplifying the design of the device.

Ultrasonic transmitters periodically transmit ultrasonic ranging signals, and an ultrasonic receiver receives the ultrasonic ranging signals on a mobile device in order to locate the mobile device in a venue. A controller determines a noise level in the venue, and varies a sound level of the periodically ranging signals based on the determined noise level, thereby optimizing the position of the mobile device.

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 goggles.