EUROFIX 導入을 위한 性能評價에 관한 硏究

Abstract

Loran-C was born in the 1950's as a long range position system for strategic weapons such as the nuclear submarine, and was developed primarily as a military system until 1974 when it became the official maritime radio-aid-to-navigation for both the U.S. and Canada.

At that time it had one or two thousand users in North America, primarily fishermen and major shipping vessels. The USSR and Eastern Block nations pursued parallel development during this period. Today there are over 1,000,000 users. Originally designed as a maritime system, widespread acceptance has been achieved with applications ranging from civil aviation and fleet management to precise time dissemination.

The introduction of satellite navigational technology back in the 1970s(TRANSIT) and the 1980s(GPS) were to be the death knell for Loran-C. Experts touted the benefits of satellite technology in the press as being the only technology anyone would require. A similar argument was made that satellite communications would one day replace all landlines, cellular and wireless systems.

The auther too, has been a leading company in radionavigation, particularly in Loran-C. Megapulse encourages and supports policies of provision of positioning, navigation and timing services by at least two independent and hybrid means-specifically GPS and Loran-C.

Megapulse substantially disagrees with policies that result in civilian sole dependency upon GPS in safety related transportation processes, and in time synchronization applications.

Today, international groups are contributing to a rebirth of Loran as a satellite augmentation adapting the EUROFIX.

EUROFIX is an integrated navigation system, which combines Differential GNSS and Loran-C. The Loran-C system is used to transmit messages which contain differential corrections and integrity information for GNSS by additional modulation of the transmitted signals. Beside differential corrections the EUROFIX datalink can also carry other information, such as differential Loran-C information or "short messages" for emergency operations in Europe and the United States.

The additional modulation should not degrade normal Loran-C operations. Restrictions on the allied modulation are imposed on the datalink design by the Loran-C user community. As data transmission is hindered by the aggressive Loran-C signal environment, special modulation patterns and Forward Error Correcting codes are designed to fulfill the requirements.

While recognizing that Loran-C is very important as a back-up for satellite systems, the introduction of EUROFIX, which uses Loran-C system, was proposed and admitted at 9th FERNS(Far East Radio Navigation System) Meeting.

But, the FERNS countries should consider whether the cost-effectiveness of the system could be improved by making use of its communication facilities to integrate more closely with satellite systems.

And, the members were requested to give this proposal consideration before the 10th session of the Council. For this matter, Korea planned to demonstrate transmitting EUROFIX signals from Pohang Loran-C station (Master of 9930 Chain) during the 10th FERNS Meetings.

Therefore, in this thesis, the introduction of EUROFIX is evaluated whether EUROFIX is suitable for reliable data transmission of DGPS signals to FERNS countries as well as South Korea, after demonstration of EUROFIX.

The demonstration result showed satisfactory enough for introduction to the FERNS member countries.