1. Technical Field
The present invention relates to a timing signal generation device, an electronic device, and a moving object.
2. Related Art
A global positioning system (GPS) is one of global navigation satellite systems (GNSS) using a satellite. An atomic clock having significantly high precision is mounted in a GPS satellite used in the GPS. A satellite signal on which orbit information, accurate time information, or the like of a GPS satellite is superimposed is transmitted to the ground. The satellite signal transmitted from the GPS satellite is received by a GPS receiver. The GPS receiver performs processing of calculating the current position or the current time information of the GPS receiver, processing of generating an accurate timing signal (1 PPS) synchronized with the coordinated universal time (UTC), or the like based on the orbit information or the time information superimposed on the satellite signal. The precision of 1 PPS depends on precision of position information of a reception point to be set, and thus, it is important to set accurate position information in the GPS receiver.
For example, a reference frequency generation device disclosed in JP-A-2011-155367 includes a GPS receiver, a rubidium oscillator, and a crystal oscillator. When the rubidium oscillator is operated normally, an output signal of the rubidium oscillator is synchronized with a reference signal (1 PPS) received by the GPS receiver, and is output as a reference frequency signal by using a first PLL circuit which includes the rubidium oscillator. When the rubidium oscillator is not operated normally, an output signal of the crystal oscillator is synchronized with a reference signal (1 PPS) received by the GPS receiver, and is output as a reference frequency signal by using a second PLL circuit which includes the crystal oscillator.
Here, in the reference signal generation device disclosed in JP-A-2011-155367, when a phase difference between the output signal of the rubidium oscillator and the reference signal is outside of a predetermined range, it is determined that the rubidium oscillator fails, and switching of the above-described PLL circuit is performed. In such a device, it is possible to detect frequency abnormality of the output signal, such as so-called frequency shift or frequency jump, in the rubidium oscillator.
However, in the reference signal generation device disclosed in JP-A-2011-155367, the cause of the frequency abnormality in the output signal of the rubidium oscillator is not recognized. Thus, there is a problem in that efficiency of work such as maintenance or repair is deteriorated.
USPTO Backgrounds
USPTO Backgrounds