Before revision: Sight is defined as the observation of the altitude, and sometimes also the azimuth, of a celestial body for a line of position; or the data obtained by such observation.The American Practical Navigator (2002) The mathematical basis of sight reductin is the circle of equal altitude.
After revision: Sight is defined as the observation of the altitude, and sometimes also the azimuth, of a celestial body for a line of position; or the data obtained by such observation.The American Practical Navigator (2002) The mathematical basis of sight reduction is the circle of equal altitude.