An apparatus can include a base assembly and a pivot assembly coupled to the base assembly. The apparatus can include a carriage coupled to the pivot assembly. The carriage can be shaped to receive a compass streamer telemetry unit (CSTU). The carriage can be configured to secure the CSTU. The pivot assembly can be rotatably coupled to the base assembly to adjust a pitch of the carriage. The carriage can be rotatably coupled to the pivot assembly to adjust roll of the carriage.

A system for determining the location of a mobile receiver unit includes static transmitter units, each including a respective clock which it uses to transmit a positioning signal according to a respective transmission schedule. The mobile receiver unit receives a positioning signal from any of the static transmitter units. A first processing means uses information relating to the received positioning signal to determine the location of the mobile receiver unit. A second processing means uses information relating to a respective drift and/or offset of each of the clocks of the static transmitter units to generate transmission schedules for the static transmitter units. Each transmission schedule instructs a respective static transmitter unit to transmit a positioning signal at one or more scheduled times according to the clock of the static transmitter unit.

A system for determining the location of a mobile receiver unit includes static transmitter units, each including a respective clock which it uses to transmit a positioning signal according to a respective transmission schedule. The mobile receiver unit receives a positioning signal from any of the static transmitter units. A first processing means uses information relating to the received positioning signal to determine the location of the mobile receiver unit. A second processing means uses information relating to a respective drift and/or offset of each of the clocks of the static transmitter units to generate transmission schedules for the static transmitter units. Each transmission schedule instructs a respective static transmitter unit to transmit a positioning signal at one or more scheduled times according to the clock of the static transmitter unit.

A hybrid infrared-ultrasound real time location system includes at least one base station having an infrared emitter and a plurality of ultrasound emitters and at least one tag. The tag receives an infrared signal from the infrared emitter and ultrasound signals from the ultrasound emitters and a time difference is determined between the time-of-arrival of the IR signal and the time-of-arrival of each ultrasound signal. Based on the time relationship of the respective transmissions of the IR signals and the US signals, the tag can measure the respective time-of-flight of each of the US transmissions from the US emitters to the tag and compute the distance from the base-station.

The present invention relates to a forward acoustic scattering based double-transmitter and double-receiver networking target detection system and method thereof. Two transmitting ends and two receiving ends are adopted, anchored at a sea bottom, and arranged in a parallelogram layout. Time of a target crossing transmitting-receiving connection lines is extracted by adopting a proper direct wave suppression method; and unknown parameters of the horizontal distance, the target velocity and the included angle between the target track and the transmitting-receiving connection lines are estimated at corresponding moving time intervals when the target crosses the four transmitting-receiving connection lines according to different crossing modes. An arrangement mode is simple and flexible, and monitoring of sea areas and sea channels can be realized. The information of the time of the target crossing the transmitting-receiving connection lines, extracted by the method, is more accurate and reliable.

The present invention relates to a forward acoustic scattering based double-transmitter and double-receiver networking target detection system and method thereof. Two transmitting ends and two receiving ends are adopted, anchored at a sea bottom, and arranged in a parallelogram layout. Time of a target crossing transmitting-receiving connection lines is extracted by adopting a proper direct wave suppression method; and unknown parameters of the horizontal distance, the target velocity and the included angle between the target track and the transmitting-receiving connection lines are estimated at corresponding moving time intervals when the target crosses the four transmitting-receiving connection lines according to different crossing modes. An arrangement mode is simple and flexible, and monitoring of sea areas and sea channels can be realized. The information of the time of the target crossing the transmitting-receiving connection lines, extracted by the method, is more accurate and reliable.

A tracking method is disclosed. The method may include displaying visual content on a screen. A base station may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. The one or more objects may be tracked so that the movement thereof may be used to alter the visual content. Such tracking may involve the base station and the one or more objects sending and/or receiving one or more ultrasonic pulses. Time-difference-of-arrival and/or time-of-flight of the one or more ultrasonic pulses may then be used to estimate a relative location and/or a relative orientation of the one or more objects with respect to the base station in three dimensional space.

The present invention is a system and method for determining the position of a transmitter relative to a receiver using ultrasound. The transmitter emits an ultrasonic sound pulse provide an indication of the time of emission of the sound electronically. A computer processor receives the time indication from the transmitter and three ultrasonic receivers positioned in a fixed arrangement. The receivers are not positioned collinearly and are spaced apart from each other by less than two times the wavelength of the sound. The computer processor estimates the relative position of the transmitter based on the time indication and time of flight of the ultrasonic sound to each of the three receivers. In preferred embodiments, the receivers are spaced apart from each other by less than the wavelength of the sound.

The present invention is a system and method for determining the position of a transmitter relative to a receiver using ultrasound. The transmitter emits an ultrasonic sound pulse provide an indication of the time of emission of the sound electronically. A computer processor receives the time indication from the transmitter and three ultrasonic receivers positioned in a fixed arrangement. The receivers are not positioned collinearly and are spaced apart from each other by less than two times the wavelength of the sound. The computer processor estimates the relative position of the transmitter based on the time indication and time of flight of the ultrasonic sound to each of the three receivers. In preferred embodiments, the receivers are spaced apart from each other by less than the wavelength of the sound.

An offshore GNSS reference station apparatus comprises: a processing resource and an underwater acoustic communications unit. The underwater acoustic communications unit comprises an underwater acoustic transducer, the underwater acoustic communications unit being arranged to cooperate with the processing resource in order to calculate a position. The apparatus also comprises a GNSS antenna site and an orientation determination unit operably coupled to the processing resource. The orientation determination unit is arranged to determine an orientation associated with the GNSS antenna site and the acoustic transducer of the underwater acoustic communications unit.