Application of non-planar four-mode differential ring laser gyroscope in high-performance dynamic angle measurement

High-performance dynamic angle measurement is an intensively researched subject, which has wide applications in various fields, such as satellite antenna, long distance telescope, etc. However, few goniometers can fulfil all the requirements of wide input range, high precision and high dynamic. Non-Planar Four-Mode Differential Ring Laser Gyroscope (NP-FMDRLG) is the so-called "next-generation" of Ring Laser Gyroscope (RLG), which is of high-precision and has no mechanical dithering parts, meeting the needs of almost all the high-performance angle measuring fields. NP-FMDRLG has no mechanical dithering parts and therefore no reaction to the rotation axis of the unit under test, feathering very low non-linearity of the scale factor, and can fulfil the measurement needs of both large and small angle, both fast and slow rotation rates. Theoretically, this paper analyzes and concludes that the bias drift is the most significant factor to the high-dynamic and high-precision angle measurement. Angle measuring precision of less than 1 arc-second is theoretically verified and experimentally demonstrated with former error analysis and field experiments. Furthermore, utilizing the ultra-high-precision rotation table SCMS-107 of the National Metrology Institutes of China (NMI), a dynamic angle measuring precision of 0.121 arc-seconds is experimentally verified. Due to the advantages stated above, NP-FMDRLG is an ideal goniometer for all high-performance and high-dynamic angle measurement areas, such as numerically controlled machine tools, high-precision rotation tables, satellite antennas, long-distance telescopes, pointing applications, etc.