UTC message broadcasting over Loran-C data channel

Although GPS has been widely used, Loran-C is still highly desirable as an alternative PRS (primary timing reference source) for an important part of a nation´s infrastructure. The current Loran-C signals lack of enough time information to flag the precision reference pulse, means that Loran-C has to be assisted by another time system in precision timing applications. In this paper, we present a new approach for the automatic independent TOC (Time of Coincidence) synchronization by Loran-C itself. Based on this method, Loran-C can be upgraded as an independent system in the aspect of precision timing. We also put forward a new message type - UTC message type, which is coincident with the latest ITU-R recommendation M589-3. The details of the message bit assignment and time code format are discussed. A precision transmission control of the UTC message is needed, so that the information and data in the message could be consistent with the reference pulse and denote the pulse. As an example, a control algorithm is given to determine and ensure the time order and position of UTC message frames.