Dissemination of UTC(NICT) by Means of QZSS

The Japanese Quasi-Zenith Satellite System (QZSS) offers the possibility to transmit information with an unprecedented bit rate of 2000 bps via the L-band experimental signal. This feature can be used to disseminate Japan Standard Time, i.e., Universal Time Coordinated (UTC)(NICT), to any user capable of receiving the new QZSS signal. Various timing transmission modes as well as a dedicated ionosphere correction model allow users to instantaneously realize UTC(NICT) across Japan with an uncertainty of a few nanoseconds. However, a sophisticated real-time ionosphere correction model also needs to be transmitted to the user to compensate for dispersive ionosphere delays which are the largest contributor to the total error budget of the system.