Abstract
Accompanied with entry into force of United Nations Convention on the Law of the Sea, it is thought that the
Exclusive Economic Zone (EEZ) will be set up in the East China Sea. In case of setting up the EEZ, the fishing
boat of each country which operate fishery around a boundary line needs to determine exactly the operation position.
Four States of Japan, Korea, China and Russia constructed Intemational Cooperative Chain of Loran C. So
the coverage of the Loran C expanded all range of the Japanese nearby seas and the East China Sea.
The authors measured a relative error of the Loran C on the basis of GPS at the East China Sea. Accuracy of
measurement position with the Loran C 9930 chain was better than that of 8930 chain. We are able to expect
the improvement of the Loran C position by setting up the correction figure of relative error with the Lorap C
to the receiver.
