Precise Determination of Astronomical Azimuth by the Hour Angle Method of Multiple Meridian Stars

Abstract

The method for precisely determining the astronomical azimuth using the local hour angle (LHA) of Polaris is only applicable in northern middle latitudes. In addition, the meridian star pair method is limited by the conditions of star selection and matching. A new hour angle method for multiple meridian stars is proposed, which is suitable for any part of the global region. When multiple south and north stars have been observed, the influence of longitude error and timing error on the azimuth is modified by linear regression. A precise astronomical position is not required, and there is no limit to the specific position of the meridian stars. Therefore, both the number of observable stars and work efficiency are greatly increased. Our experiment indicates that the results of the new method can reach the first-order accuracy level; i.e., the root mean square error (RMSE) is less than 0.5″, even when the amount of observed data is reduced to half that of the Polaris method.