三本の位置の線による船位誤差界の実用解(日本航海学会第19回講演会)

抄録

The writer made careful examination of every method to express the error boundaries of ship's positions fixed by two position lines, in the former paper ; he concluded that the probable ellipse system was the excellent one, theoretically and practically. However, in the case of fix by three position lines, to draw an ellipse, three quantities (the length of major axis, the length of minor axis, the orientation of the major axis) are necessary and yet one can not find an approximation to do it, accordingly troublesome construction is necessary. The writer studied on 95 per cent probable circle to meet the convenience of practicality. By making use of this method one can easily draw 95 per cent probable boundaries, in the case when the accuracies of three position lines are alike, by means of a single quantity.