| Because the stars, sun, and moon are available most of the time throughout the world, celestial navigation is a useful means to determine your position and cross-check the accuracy of your GPS. Each celestial observation you take provides an LOP or line of position. During the day, when the sun may be the only visible body, this kind of navigation will mean using single LOPs. Fortunately, about half the time the moon is also visible during the day, and can provide a second LOP to give you a fix. Continue reading “Basic Celestial Concepts” |