Direct Methods of Latitude and Longitude Determination by Mini-Computer

Abstract

In celestial navigation, the advent of the hand held or mini-computer brought forth a plethora of methods for the solution of spherical triangles. The azimuths and altitudes thus derived have not only eliminated the need for bulky tables but also have speeded up the determination of the data needed for the graphic construction of intersecting lines of position from which the “fix” is derived. In this conventional type of solution, the corrected sextant altitude is compared with the computed altitude then, from the assumed position, the line of position is constructed perpendicular to the azimuth of the body observed and either towards the body or away from it depending upon whether the observed altitude is greater or less, respectively, than that which has been computed. Extremely sophisticated systems are being developed which combine special computer systems directly with the sextant. However, the present paper relates only to the minicomputers currently on the market and their apparent ultimate utility in the celestial navigation field—the direct display of both latitude and longitude without recourse to graphic methods.