A satellite radio-controlled watch, including a receiving unit for receiving a satellite radio wave containing time information and position information; a storage unit for storing intersection point information indicating a position of an intersection point between a reference line along a great circle orthogonal to a specific great circle on the earth or a reference line along the specific great circle on the earth or a circle parallel to the great circle and a time zone boundary, and time difference division information on a wedge-shaped or belt-shaped area that is adjacent to the reference line and to which the intersection point belongs, and a time zone determination unit for determining a time zone, based on the position information, the intersection point information, and the time difference division information.

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.

Example embodiments relate to GNSS time synchronization in redundant systems. A redundant system configured with two subsystems may initially synchronize clocks from both subsystems to GNSS time from a GNSS receiver. The synchronization of the first subsystem's clock may involve using a first communication link that enables communication between the first subsystem and the GNSS receiver while the synchronization of the second subsystem's clock may involve using both the first communication link and a second communication link that enables communication between the subsystems. The redundant system may then synchronize the first subsystem's clock to the second subsystem's clock while the second subsystem's clock is still synchronized to GNSS time from the GNSS receiver based on timepulses traversing a pair of wires that connect the subsystems and the GNSS receiver.

Example embodiments relate to GNSS time synchronization in redundant systems. A redundant system configured with two subsystems may initially synchronize clocks from both subsystems to GNSS time from a GNSS receiver. The synchronization of the first subsystem's clock may involve using a first communication link that enables communication between the first subsystem and the GNSS receiver while the synchronization of the second subsystem's clock may involve using both the first communication link and a second communication link that enables communication between the subsystems. The redundant system may then synchronize the first subsystem's clock to the second subsystem's clock while the second subsystem's clock is still synchronized to GNSS time from the GNSS receiver based on timepulses traversing a pair of wires that connect the subsystems and the GNSS receiver.

A GPS receiving apparatus according to the present invention includes: a GPS radio wave receiving unit that receives GPS radio waves; a walking state determination unit that determines a walking state of a wearer continuously for a predetermined interval; a storage unit that stores walking information determined by way of the walking state determination unit; a determination unit that determines whether being a state in which GPS radio waves can be received, based on a series of the walking states stored in the storage unit; and a control unit that causes reception of GPS radio waves to be carried out by way of the GPS radio wave receiving unit, in a case of being determined by way of the determination unit as being a state in which GPS radio waves can be received.

A GPS receiving apparatus according to the present invention includes: a GPS radio wave receiving unit that receives GPS radio waves; a walking state determination unit that determines a walking state of a wearer continuously for a predetermined interval; a storage unit that stores walking information determined by way of the walking state determination unit; a determination unit that determines whether being a state in which GPS radio waves can be received, based on a series of the walking states stored in the storage unit; and a control unit that causes reception of GPS radio waves to be carried out by way of the GPS radio wave receiving unit, in a case of being determined by way of the determination unit as being a state in which GPS radio waves can be received.

An electronic device includes a dial, a module and a solar panel. The module is arranged under the dial and including a circular polarization antenna which includes a power feed point and a radiating electrode. The solar panel is arranged between the dial and the module and has an area corresponding to an area of the dial in a face direction thereof. The solar panel is constituted by a plurality of solar cells including a solar cell that has a light receiving surface arranged at a position corresponding to the radiating electrode.

An electronic device includes a dial, a module and a solar panel. The module is arranged under the dial and including a circular polarization antenna which includes a power feed point and a radiating electrode. The solar panel is arranged between the dial and the module and has an area corresponding to an area of the dial in a face direction thereof. The solar panel is constituted by a plurality of solar cells including a solar cell that has a light receiving surface arranged at a position corresponding to the radiating electrode.

A satellite signal receiving device having a receiver circuit that receives a satellite signal transmitted from a positioning information satellite further includes a solar cell that converts light energy to electrical energy; a generating state detection circuit that detects a generating state of the solar cell to obtain a detection value, which is a power generating evaluation time, which is a time during which the solar cell output is continuously in a high illuminance state; and a control circuit that controls the receiver circuit and the generating state detection circuit, sets a threshold value for the power generating evaluation time, and compares the detection value with the threshold value and operates the receiver circuit when the detection value is greater than or equal to the threshold value. The control circuit changes the threshold value for the power generating evaluation time when satellite signal reception failed.

A satellite signal receiving device having a receiver circuit that receives a satellite signal transmitted from a positioning information satellite further includes a solar cell that converts light energy to electrical energy; a generating state detection circuit that detects a generating state of the solar cell to obtain a detection value, which is a power generating evaluation time, which is a time during which the solar cell output is continuously in a high illuminance state; and a control circuit that controls the receiver circuit and the generating state detection circuit, sets a threshold value for the power generating evaluation time, and compares the detection value with the threshold value and operates the receiver circuit when the detection value is greater than or equal to the threshold value. The control circuit changes the threshold value for the power generating evaluation time when satellite signal reception failed.