A time synchronization method that is capable of selecting whether synchronization, by a timepiece unit that generates a time signal synchronized with a standard time and outputs it to an exterior, with the time is performed by time information obtained by receiving a radio wave including information relating to the time, or is performed by means of a holdover performed using a clock signal from an internal or external clock source. A schedule having a first time period in which the above-mentioned time information is used, and a second time period by means of the holdover is determined according to temporal reception characteristics of the radio wave at a reception location of the radio wave, and according to the schedule, supplying the timepiece unit with the time information or supplying the timepiece unit with the clock signal from the internal or external clock source.

An electronic watch includes a navigation processor that perform navigation processing of causing a positioning processor to perform positioning processing, and calculating a distance to a destination based on current position information acquired by the positioning processing and destination position information, and also calculating a direction of the destination based on current position information, geomagnetism, and destination position information, and moreover causing a display unit to display the direction of the destination, and an operation device configured to case the navigation processor to start navigation processing when a predetermined operation is performed. The navigation processor performs, when the distance is longer than a preset threshold, the navigation processing at a first frequency during a predetermined time after predetermined operation is performed, and performs, when the distance is shorter than or equal to a preset threshold, the navigation processing at a second frequency higher than first frequency during the predetermined time.

A time synchronizer receives UTC (Coordinated Universal Time) time in serial+PPS (Pulse Per Second) format from a GPS (Global Positioning System) device and outputs timestamp data in multiple formats, including: CAN (Controller Area Network), Ethernet, gPTP (generic Precision Time Protocol), and serial+PPS. Multiple data sources receive timestamp data in the multiple formats and each provide data in a unified UTC time base to a sensor-fusion device. The unified UTC time base is based on the timestamp data in the multiple formats output by the time synchronizer. The time synchronizer may perform edge detection for a first transition of an internal clock signal following a transition of the PPS signal received from the GPS device. The internal clock signal may be asynchronous with the PPS signal received from the GPS device. The internal clock signal may have a frequency of 40 MHz.

A time synchronizer receives UTC (Coordinated Universal Time) time in serial+PPS (Pulse Per Second) format from a GPS (Global Positioning System) device and outputs timestamp data in multiple formats, including: CAN (Controller Area Network), Ethernet, gPTP (generic Precision Time Protocol), and serial+PPS. Multiple data sources receive timestamp data in the multiple formats and each provide data in a unified UTC time base to a sensor-fusion device. The unified UTC time base is based on the timestamp data in the multiple formats output by the time synchronizer. The time synchronizer may perform edge detection for a first transition of an internal clock signal following a transition of the PPS signal received from the GPS device. The internal clock signal may be asynchronous with the PPS signal received from the GPS device. The internal clock signal may have a frequency of 40 MHz.

An optical communication device including a GPS receiver receiving and outputting a GPS signal from a satellite; a main controller configured to generate and output synchronization data based on the GPS signal; and an optical transceiver configured to generate an optical signal by superposing input payload data and the synchronization data, and to output the optical signal, wherein a first communication channel corresponding to the payload data and a second communication channel corresponding to the synchronization data are different communication channels. According to embodiments, GPS information for synchronization together with payload data, which is information to be transmitted, may be efficiently transmitted between optical communication devices located in remote locations without separate wavelength allocation and connection of an optical cable, by using an auxiliary management and control channel (AMCC).

An optical communication device including a GPS receiver receiving and outputting a GPS signal from a satellite; a main controller configured to generate and output synchronization data based on the GPS signal; and an optical transceiver configured to generate an optical signal by superposing input payload data and the synchronization data, and to output the optical signal, wherein a first communication channel corresponding to the payload data and a second communication channel corresponding to the synchronization data are different communication channels. According to embodiments, GPS information for synchronization together with payload data, which is information to be transmitted, may be efficiently transmitted between optical communication devices located in remote locations without separate wavelength allocation and connection of an optical cable, by using an auxiliary management and control channel (AMCC).

An unmanned aerial vehicle manages storage of data and transfer between other connected devices. The unmanned aerial vehicle captures sensor data from sensors on the unmanned aerial vehicle. The unmanned aerial vehicle transfers the captured sensor data from the unmanned aerial vehicle to a remote controller via a wireless interface. The captured data may be transferred via a TCP link, a UDP link, or a combination thereof If a loss of link is detected, the captured sensor data is stored to a buffer and a battery level of the unmanned aerial vehicle and a flight status of the unmanned aerial vehicle is monitored. The stored sensor data is transferred from the buffer to a non-volatile storage responsive to the battery level dropping below a predefined threshold or detecting that the unmanned aerial vehicle is stationary and a shutdown may be imminent.

An unmanned aerial vehicle manages storage of data and transfer between other connected devices. The unmanned aerial vehicle captures sensor data from sensors on the unmanned aerial vehicle. The unmanned aerial vehicle transfers the captured sensor data from the unmanned aerial vehicle to a remote controller via a wireless interface. The captured data may be transferred via a TCP link, a UDP link, or a combination thereof If a loss of link is detected, the captured sensor data is stored to a buffer and a battery level of the unmanned aerial vehicle and a flight status of the unmanned aerial vehicle is monitored. The stored sensor data is transferred from the buffer to a non-volatile storage responsive to the battery level dropping below a predefined threshold or detecting that the unmanned aerial vehicle is stationary and a shutdown may be imminent.

An electronic timepiece enables displaying multiple times and easily correcting the displayed time. An electronic device has a correction mode setting unit that sets a first time correction mode for adjusting a first time, or a second time correction mode for adjusting a second time, in response to a correction mode setting operation; and a display control unit that moves an indicator hand to a first indicated position indicating that the hands to be corrected are first hands when the first time correction mode is set, and moves the indicator hand to the second indicated position indicating that the hands to be corrected are second hands when the second time correction mode is set.

An electronic timepiece enables displaying multiple times and easily correcting the displayed time. An electronic device has a correction mode setting unit that sets a first time correction mode for adjusting a first time, or a second time correction mode for adjusting a second time, in response to a correction mode setting operation; and a display control unit that moves an indicator hand to a first indicated position indicating that the hands to be corrected are first hands when the first time correction mode is set, and moves the indicator hand to the second indicated position indicating that the hands to be corrected are second hands when the second time correction mode is set.