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.## INTRODUCTION AND INDEX - - 08/04/2014

A1 The rhumb line, ( graphical Mercator sailing and middle latitude sailing )## NAVIGATION TRIGONOMETRY INDEX

A2 Calculated Mercator sailingB1 Definitions, the spherical triangle

B2 The right spherical triangle

B3 The oblique spherical triangleC1 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 methodD1 Approximation methods for great circle sailing

D2 Graphical great circle sailing

D3 Calculated great circle sailingE1 The Marine sextant

E2 The Sumner line

E3 Spherical coordinates

E4 Sight Reduction

E5 Sight Reduction Formulas

E6 The Nautical Almanac

E7 Sight Reduction SummaryF1 Selected Navigation Stars (west to east)

F2 Selected Navigation Stars (alphabetical)

F3 Selected Navigation Stars (for northern hemisphere)