In a positioning system, a plurality of transmitter units (2, 3, 4, 5) transmit respective transmitter-specific identification signals at intervals, which are received at a mobile receiver unit (7). A processing system (7; 9) identifies the transmitter unit that transmitted each received identification signal, and, for each signal, determines range data from time of arrival data and determines distance data from Doppler shift information. The range data and distance data are compared to determine range error data. A position estimate for the mobile receiver unit (7) is determined by solving an optimisation problem using range estimates determined for the plurality of transmitter units, weighted in dependence on the range error data.

In a positioning system, a plurality of transmitter units (2, 3, 4, 5) transmit respective transmitter-specific identification signals at intervals, which are received at a mobile receiver unit (7). A processing system (7; 9) identifies the transmitter unit that transmitted each received identification signal, and, for each signal, determines range data from time of arrival data and determines distance data from Doppler shift information. The range data and distance data are compared to determine range error data. A position estimate for the mobile receiver unit (7) is determined by solving an optimisation problem using range estimates determined for the plurality of transmitter units, weighted in dependence on the range error data.

The present invention provides a method and system for real-time high-precision positioning in the deep sea. The present invention, based on a ray theory model, uses an azimuth angle, a transmission delay, a deep-sea vehicle depth and a depth of an acoustic transducer of a water surface monitoring platform as an eigenray emergence angle, an eigenray transmission time, eigenray emergence depth and an eigenray end point depth respectively, quickly calculates an eigenray that connects the water surface monitoring platform with the deep-sea vehicle, accurately calculates a position of the deep-sea vehicle relative to the water surface monitoring platform, and converts the position into absolute position information of the deep-sea vehicle through the latitude and longitude of the water surface monitoring platform, thereby achieving real-time high-precision positioning.

The present invention provides a method and system for real-time high-precision positioning in the deep sea. The present invention, based on a ray theory model, uses an azimuth angle, a transmission delay, a deep-sea vehicle depth and a depth of an acoustic transducer of a water surface monitoring platform as an eigenray emergence angle, an eigenray transmission time, eigenray emergence depth and an eigenray end point depth respectively, quickly calculates an eigenray that connects the water surface monitoring platform with the deep-sea vehicle, accurately calculates a position of the deep-sea vehicle relative to the water surface monitoring platform, and converts the position into absolute position information of the deep-sea vehicle through the latitude and longitude of the water surface monitoring platform, thereby achieving real-time high-precision positioning.

A method for finding door location in an automated way based on observations of people that are equipped with a device whose position is determined acoustically. By observing positioning transitions across internal structures such as walls, the location of doors can be automatically identified.

A method for finding door location in an automated way based on observations of people that are equipped with a device whose position is determined acoustically. By observing positioning transitions across internal structures such as walls, the location of doors can be automatically identified.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

Disclosed are a system for identifying the position of mobile object, comprising a positioning module, a set of beacons and processor configured to determine the position of the positioning module based on the data gathered from the interaction between the positioning module and each one of the set of beacons. More specifically, the limited area positioning system utilizes signal emitted from the positioning module and the signals emitted from the each of the beacons in response to the signal from the positioning module. Using the signals transmitted from the positioning module and the beacons, at least three circles can be formed, and the limited area positioning system determines the intersecting point of those three circles as the position of the positioning module.

The present invention relates to an ultrasound-based system for localizing a medical device within the field of view of an ultrasound imaging probe. A localization system is provided that includes at least three ultrasound emitters that are arranged on a frame; and a position triangulation unit. The frame is adapted for attachment to an ultrasound imaging probe. The position triangulation unit determines a spatial position of the ultrasound detector relative to the at least three ultrasound emitters based on signals received from an ultrasound detector that is attached to the medical device. The frame includes a detachable reference volume comprising a background volume and an inclusion or void. When the detachable reference volume is attached to the frame and the frame is attached to the ultrasound imaging probe the inclusion or void provides a corresponding image feature within the field of view of the ultrasound imaging probe for use in calibrating the field of view of the ultrasound imaging probe with the coordinate system of the localization system.