Abstract
Mr. Y. Namikawa and I had studied the contours of constant probability density of Loran fixes gotten through the triplet; the stations of two pairs with the common master station. And then, I studied Loran quadrilateral and the special cases of two separate pairs of Loran stations, and drew the figures of contours of constant probability density in each of them. (Fig 1〜Fig 8) By those figures, it was evidently shown that the most advantageous arrangement of two pairs was the Loran quadrilateral, and that secondary was the triplet, and that two separate pairs were of no use to obtain the precise fix generally.
