Intercept Plotter Tool

Celestial Navigation Chartting Using

The Intercept Method

A celestial navigation technique used to determine your location by celestial bodies is called the "intercept method". This method uses an assumed geographic position, the current GMT time, and a celestial body to calculate the alttitude about the horizon at which body should be located. This calculated altitude is compared to the observered altitude to determine the delta distance and direction of the observer from the assumed position. This delta position is called the intercept. By sighting of shooting several different celestial bodies and calculating the intercepts a navigator can determine their approximate position based on the intersection point of the the intercepts.

These web pages are not meant to instruct in the practice of celestial navigation. There are numerous books, classes, and web sites which cover the theory and practice and as such adding another voice to this chorus is more likely to confuse then educate. Several books and web site links are listed on the side bar and the curious are encouraged to follow these links.

The purpose of these pages is the description and delivery of a web based charting tools which allows a navigator to enter their observed and calculated information and plot the intercepts against a web based map.

Last changed April 3, 2008