Orientation method based on lunar hour angle

Abstract Astronomical orientation is a crucial technique for obtaining high-precision azimuths. However, at night, this often relies on the North Star, which can be challenging to locate and identify. An orientation method is proposed based on the lunar hour angle as an alternative. By applying theories from astronomy and geodesy, we conduct an in-depth study of the key points and calculation steps for using a theodolite to measure the moon. By observing the moon’s edge and center and combining this with the observer’s geographic location and observation time, we calculate the lunar hour angle to determine the true north azimuth. To improve computational efficiency, an application has been developed to assist with observation and data processing. Practical applications and tests have validated the feasibility and effectiveness of this lunar hour angle-based orientation method. This method addresses the limitations of traditional North Star orientation, offering an efficient and convenient approach to orientation.