Polar Navigation

Résumé

Statement (in detail) of the principles on which operational techniques of polar grid navigation are based, the system tested in May 1945 in the north polar flights of the Aries, and used in long-range flights of the U.S.A.F., R.C.A.F., and R.A.F. into very high latitudes. The major part of the author's original paper on the subject (written in 1941) dealing with measurement of direction in polar latitudes is published here for the first time. "The portions omitted concern the design and use of 'astrographs', a type of navigation instrument...now considered obsolete."