The time of transmission and reception between stations A and B is exchanged, and any deviation in time is calculated in a corresponding manner in the stations. Using the transmission time TXA from station A to B, the transmission time TYB from station B to A, the time TXB of a clock at station B in a transmission from station A to station B, and the clock time TYA at station A in a transmission from station B to A, the following are measured in sequence: 1) station A records the time TXA at which TXA and TYA were transmitted, 2) station B measures the time TXB at which TXA and TYA were received, 3) station B records the time TYB at which TXB and TYB were transmitted, and 4) station A measures the time TYA at which TXB and TYB were received, the transfer time between stations A and B being derived at each station on the basis of the average of the increase TXB-A from TXA to TXB and the increase TYA-B from TYB to TYA, or the deviation in time for a transfer between stations A and B being determined by subtracting the increase TXB-A from the transfer time. The transmission time TXA from station A to B may also be measured using a reflection signal from a transmission terminal.

A compensation circuit for an oven-controlled crystal oscillator serving as a reference for a phase-locked loop in holdover mode is disclosed. A non-linear function module generates a modified aging signal that is a non-linear function of an aging signal. A first Kalman filter generates an estimate of the frequency drift of the crystal oscillator based on the temperature signal. A second Kalman filter generates an estimate of the frequency drift based on the modified aging signal. A combining and comparing module combines the estimates generated by the first and second Kalman filters and compares the estimates with detected frequency drift to produce an error signal to update the Kalman filters. In holdover mode the Kalman filters generate an error signal to correct the oscillator frequency based on updates obtained during operation of the phase-locked loop in normal mode.

A device having: one or more processors for determining an elapsed time since a correction of a calculated date and time; estimate a degree of deviation included in the calculated date and time, based on the elapsed time; and in response to estimating the degree of deviation to be equal to or smaller than a predetermined range, execute a method by which the one or more processors: generate an expected code sequence of a code sequence to be received from a satellite; control a satellite radio wave receiver to receive the code sequence; determine whether there is a match between the expected code sequence and the code sequence; in response to determining that there is a match, obtain a present date and time information represented by the expected code sequence; and correct the calculated date and time, based on the present date and time information obtained.

Systems, methods, and devices of the various embodiments may provide for synchronizing clocks across a distributed network of nodes. Various embodiments include an autonomous distributed fault-tolerant local positioning system, a fault-tolerant GPS-independent autonomous distributed local positioning system, for static and/or mobile objects, and/or solutions for providing highly-accurate geo-location data for static and/or mobile objects in dynamic environments. Various embodiments enable faulty Echo message recovery using trilateration from locally time-stamped events obtained from other nodes in a distributed network of nodes. Using the faulty Echo message recovery techniques, in addition to clock synchronization various embodiments may enable object detection and location.

A method for sensor operation includes deploying a network of sensors, which have respective clocks that are not mutually synchronized. At least a group of the sensors receive respective signals emitted from each of a plurality of sources, and record respective times of arrival of the signals at the sensors according to the respective clocks. Location information is provided, including respective sensor locations of the sensors. The respective clocks are synchronized based on the recorded times of arrival and on the location information. In the process the sources may be localized, or if the sources are far away, then their directions may be resolved. Sensor positions may also be resolved in the process.

An electronic device and time piece are shown. The electronic device includes: a plurality of antenna devices; a plurality of motors; and antimagnetic plates, each fully or partially covering the motors and having cutouts at positions overlapping with the antenna devices.

Sensor modules are triggered to start and stop the measurement approximately synchronously by sending a broadcast message. Information on the timeline of local clocks is also collected by local counters, and any relative differences in the local clocks, local sample clocks or local time stamps are rectified afterwards by means of the collected timeline information.

An embodiment of a device comprising one or more processors, the one or more processors configured to acquire time information by performing one or more of a first acquisition operation to control a communicator to communicate with an external device to receive signals including the time information, and a second acquisition operation to control one or more radio wave receivers to receive transmission radio waves with signals including the time information.

An electronic timepiece includes a display section capable of displaying reception state information based on the strength of a received satellite signal or the number of captured satellites during the execution of a reception process. In a case where a predetermined period has elapsed with no acquisition of time information or position information since the reception process started, the reception state information is displayed on the display section, and in a case where the time information or the position information has been successfully acquired within the predetermined period since the reception process started, the reception state information is not displayed on the display section but the reception process is terminated.

A method for transmitting data or sensor data by radio between a preferably fixed battery-operated node and base station in a communication system with bidirectional radio transmission, includes providing a base station communication module having a first frequency transmitter, and a node communication module having a first frequency transmitter and second frequency transmitter with lower frequency. The node communication module transmits data in the uplink to the base station communication module by splitting a radio telegram into data packets transmitted successively with temporal spacing. The base station communication module transmits data in the downlink to the node communication module by splitting a radio telegram into data packets transmitted successively with temporal spacing. To improve downlink reception quality, two calibrations of first and second node frequency transmitters occur during transmission of the sum of a sequence of uplink data packets and subsequent sequence of downlink data packets including periods therebetween.