A Short Guide to Celestial Navigation [zipped pdf]
This guide provides a concise overview of celestial navigation principles and techniques, covering key concepts like using a sextant, identifying celestial bodies, and calculating position from sights. It is presented as a downloadable zipped PDF file.
Background
- Celestial navigation (or "celnav") is the art of finding a ship's position at sea by measuring the angle of the Sun, Moon, stars, or planets above the horizon using a sextant. It was the primary method of ocean navigation before GPS.
- The linked page offers a free, concise PDF guide on how to perform these calculations by hand — aimed at sailors, hobbyists, and preppers who want a backup navigation skill independent of satellites.
- Key concepts covered include: taking a "sight" (measurement) with a sextant, correcting for refraction and dip (errors introduced by the atmosphere and the observer's height), sight reduction (converting that measurement into a line of position), and plotting a fix from multiple celestial bodies.
- A working knowledge of basic spherical trigonometry and the ability to use a Nautical Almanac (a yearly table of celestial bodies' positions) are prerequisites.