関東南方域におけるロランCの精度評価

抄録

This study was conducted for the purpose of evaluating the accuracy of the observed Time Difference (TD) in Loran-C when the ground wave propagates on the surface included both land and sea. The TD of W, X and Y in North West Pacific Chain GRI9970 was measured at 50 points in southern Kanto area-Tokyo, Miura Peninsula and Izu islands. The results obtained are summarized as follows; (1) Most of the standard deviations in the TD of W, X and Y which are obtained from the continuous observation at Tokyo moniter station are about 0.1μs. This means high repeatability accuracy in the line of position. (2) The more land distance included in propagation path is longer, the more lag of the arrival time from Loran-C station becomes larger. (3) Errors of the TD at spindle shaped O Sima increased in proportion to difference of mountain height on propagation path, and the average rate of increase was 0.1μs/100m. (4) Error of the TD by irregular terrain was reduced rapidly as going far off from coastal line.