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In recent years, the laser gyro SINS has made great progress. The long-term experiments show that the attitude precision of laser gyro strapdown inertial navigation is equal to that of photoelectric theodolite. At present, the astronautical survey vessel uses the theodolite to measure the star to calibrate the platform inertial navigation. Each individual error check of the theodolite can only be carried out in the dock. In order to realize the regular inspection and calibration of the ship theodolite, the standard calibration method was adopted instead of the light pipe method, and the original calibration work in the dock was transferred to the sea. According to the error characteristics of theodolite, the error calibration model of the theodolite calibration error is established. Real-time high-precision attitude data of laser gyro strapdown inertial navigation is used to overcome the influence of ship shake, and the individual error values are obtained by least square method. Experiments show that the singular errors can be obtained by using the inertial aided asteroid calibration. It is found that the parameters obtained by the astral calibration are basically the same as those obtained from the standard calibration in the docking station.

This report investigated dislocation–twin boundary (TB) interactions that cause the TB to disappear and turn into a high-angle grain boundary (GB). The evolution of the microstructural characteristics of Hadfield steel was shown as a function of severe plastic deformation processing time. Sessile Frank partial dislocations and/or sessile unit dislocations were formed on the TB through possible dislocation reactions. These reactions induced atomic steps on the TB and led to the accumulation of gliding dislocations at the TB, which resulted in the transition from coherent TB to incoherent GB. The factors that affect these interactions were described and a physical model was established to explain in detail the feasible dislocation reactions at the TB.