. Electronic navigational aids; loran, radiobeacon, and radarbeacon systems and loran, radio-direction-finder, and radar ship equipment. Loran; Radar. 24 OCEAN ELECTRONIC NAVIGATIONAL AIDS excepting during fog, advantage should be taken of bearings at suitable angles as opportunity offers. The common method of locating a ship by cross bearings may be employed in radio navigation using two or more radiobeacons, or visual and radio bear- ings in combination. Of course, the usual principles apply as to employing stations which will give good intersections, and as to allowing for the distance run
. Electronic navigational aids; loran, radiobeacon, and radarbeacon systems and loran, radio-direction-finder, and radar ship equipment. Loran; Radar. 24 OCEAN ELECTRONIC NAVIGATIONAL AIDS excepting during fog, advantage should be taken of bearings at suitable angles as opportunity offers. The common method of locating a ship by cross bearings may be employed in radio navigation using two or more radiobeacons, or visual and radio bear- ings in combination. Of course, the usual principles apply as to employing stations which will give good intersections, and as to allowing for the distance run between the times of taking bearings if the interval is appreciable. United States radiobeacons are operated at intervals on a fixed time schedule in clear weather and continuously during fog; adjacent stations send for successive minutes. This facilitates the taking of radio cross bearings, as does also the location in important localities of two or three stations sufficiently close for cross bearings. Radiobeacons in the approaches to New York, illustrating their use in navigation, are shown in figure 2-3. Figure 2-4 illustrates how in actual practice a navigator may fix his position by cross bearings on three Pacific coast radiobeacons. The angles between the stations in figure 2-4 are not such that a small triangle of most probable position will be formed as in figure 2-3. Such cases are common along some steamship routes, but the fixes are extremely valuable, nevertheless, and may be good despite the small angle at which two of the lines cross. It will be noted that in figure 2-4 the correctness of the bearing of the station to the north is confirmed or independently checked by that of the station to the south to give the distance off-shore, while bearing of the station to ths east gives a cut at a good angle to determine the progress of the vessel along the coast. For additional information on accuracy of bearings, plotting, and other matters, the navigator should consult
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