Performance and accuracy monitoring of geodetic instruments

Abstract

The accuracy of an output signal of an information-measuring system determines the main parameters of instrument's performance. Together with instrument's performance monitoring, accuracy monitoring gives the most important information about both features. The measuring system of an instrument is calibrated against the reference standards of measure comparing its accuracy at some intervals of calibration. It depends on written standards and technical specifications for these instruments. Geodetic instruments, rotary tables of metal cutting tools and instruments, linear and rotary encoders produce a great number of discrete values. The theoretical and technical background for monitoring the accuracy of performance of angular and linear measurement instruments used in geodesy and machine engineering there is described. A test rig for angular accuracy monitoring is presented. The main concepts of circular scales measurement were chosen as the basis for developing of a monitoring system. Since circular scales are employed in almost all measurement systems and rotary encoders, they play an important role in the method of monitoring of their accuracy parameters. The new scale calibration method is discussed that is applied for extensive and informative monitoring and assessment of performance and accuracy of geodetic instruments.