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The following is a short review of spherical trigonometry, celestial navigation, and great circle sailing. The solution of the navigation triangle (section C) can be used for great circle course determination and for determining a location of the observer from astronomical observations. There are many ways to solve spherical triangles, but my interest in this discussion are those methods that can be used on a calculator without the need of special tables.

A1 The rhumb line, ( graphical Mercator sailing and middle latitude sailing )
A2 Calculated Mercator sailing

B1 Definitions, the spherical triangle
B2 The right spherical triangle
B3 The oblique spherical triangle

C1 The navigation triangle using the law of cosines
C2 The navigation triangle using the Ageton method
C3 The navigation triangle using Napier's analogies
C4 The navigation triangle using the no-name method

D1 Approximation methods for great circle sailing
D2 Graphical great circle sailing
D3 Calculated great circle sailing

E1 The Marine sextant
E2 The Sumner line
E3 Spherical coordinates
E4 Sight Reduction
E5 Sight Reduction Formulas
E6 The Nautical Almanac
E7 Sight Reduction Summary

F1 Selected Navigation Stars (west to east)
F2 Selected Navigation Stars (alphabetical)
F3 Selected Navigation Stars (for northern hemisphere)

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