FINDING LATITUDE AND LONGITUDE BY CALCULATORS

C. Fox

Peer Reviewed

Abstract: To find two unknowns L, the latitude, and X, the longitude, two equations are required. The navigator constructs the navigational triangles of two stars and obtains two equations for L and X. Unfortunately it is almost impossible to solve these equations for L and X, because of the difficulty of separating the L terms from the X terms. I consider here the case where the navigator constructs the navigational triangles of three stars and so obtains three equations involving L and X. If the two time intervals between the measurements of the altitudes of the three stars are small enough one obtains a set of three equations from which L and X can be easily found with reasonable accuracy. If this accuracy is not good enough another set of three equations can be obtained from which L and X can be found by the method of Successive Approximations, 89. Thii method gives good accuracy even if the time intervals are not so small. Many modern calculators can perform arithmetical and trigonometrical operations of great complexity. Some can carry out programs of prescribed operations many times over. Such calculators can perform all the computations required in the methods briefly described above and can relieve the navigator of all the tedium of computation.
Published in: NAVIGATION, Journal of the Institute of Navigation, Volume 22, Number 4
Pages: 293 - 301
Cite this article: Fox, C., "FINDING LATITUDE AND LONGITUDE BY CALCULATORS", NAVIGATION, Journal of The Institute of Navigation, Vol. 22, No. 4, Winter 1975-1976, pp. 293-301.
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