Data processing method of calculating wobble error with level instrument

Data processing method of calculating wobble error with level instrument REN Shun-qing, WANG Jun-zhu (Space Control and Inertial Technology Research Center, Harbin Institute of Technology, Harbin 150001, China, E-mail; renshq@yahoo.com.cn) Abstract; Aiming at the shortcomings in data process of measuring the wobble error of vertical axis system, the attitude relationships between the level instrument coordinate system and the standard coordinate system is deduced by establishing 4 coordinate systems, and the measurement theory of the wobble error is expounded. Perpendicularity error of the axis line versus the horizontal plane is measured precisely by carrying out discrete Fourier transformation of the readouts of level instrument. When the perpendicularity error and the mean value are taken off from die readouts, the part of the 1 st torder harmonic error and all the 2nd torder harmonic error in wobble error is reserved. Finally, wobble error of an axis system is measured by a precision level instrument, and the method in this paper is proved to be more rational than the traditional method by the practical measurement data.