Gauss’ method of celestial navigation

One of the most important problems in maritime navigation is that of finding the ship’s position at sea. Nowadays, the ship’s position can be determine using Global Navigation Satellite Systems (GNSSs); however, celestial navigation methods are still taught and can be used as a second line method in case the GNSS fails. In this paper, we present a method proposed by Carl Gauss, in 1809, to determine the ship’s position at sea. The method proposed requires only the observation of two altitudes of the Sun at two different instants of the day and calculates the geographical position of the ship without the need of other information such as assumed position or the use of the Nautical Almanac. This self-contained method was implemented in an Excel spreadsheet and was tested using real observations of the Sun. The results obtained were compared with the GPS (Global Positioning System) coordinates and we concluded that the results are extremely satisfactory. The method proposed represents a good alternative when the electronic systems fail.