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原文传递 Land Navigation in the Kimberleys Utilising Differential Omega.

题名：	Land Navigation in the Kimberleys Utilising Differential Omega.
作者：	Silby,J. H.;Edgar,R. S.;
关键词：	OMEGA NAVIGATION, IONOSPHERE, DEGRADATION, CORRELATION, NIGHT, AUSTRALIA, DIURNAL VARIATIONS, LAND AREAS, VERY LOW FREQUENCY.
摘要：	It was demonstrated that differential Omega provides effective daylight navigation in the Kimberley region of Western Australia when using transmissions from Omega Japan, Reunion and Australia. Of the measurments carried out on two occasions between 0830 and 1630 local time on 13.6 kHz at Sandfire Flat, Pt Hedland, Fitzroy Crossing and Halls Creek (with the base station located at Broome), 89%fell within 250 m of the true position; this figure degraded to 81%when readings taken at Derby were included. Of the readings taken on 11-1/3 kHz at Sandfire Flat, Fitzroy Crossing, Halls Creek and Derby, 93%fell within 250 m; the figure degraded to 72%when Pt Hedland readings were included. In the computations, standard values were assumed for phase velocity over sea paths; for land paths values of 1 part in 1000 lower were assumed, corresponding to earth conductivity of 0.001 mho/m except in the case of the Reunion transmission on 13.6 kHz where a better fit was obtained for a figure of 2 parts in 10,000. Ionospheric decorrelation between base and field sites was found to be severe at night with degradation setting in during late afternoon. Positional errors of up to 3 km could be expected from this cause.
总页数：	82
报告类型：	科技报告