State primary special standard of the unit of length GET 199-2024: ensuring the uniformity of measurements of high-precision total stations and their analogues in the mode of three-dimensional measurements

The metrological support of optical-electronic means of measuring spatial coordinates is described. To meet modern consumer requirements for the accuracy of measurements of spatial coordinates with electronic tacheometers and their analogues (laser scanners, absolute trackers), the State primary special standard of the unit of length GET 199-2024 includes technical means for reproducing, storing and transmitting the unit of length in three-dimensional measurement mode. A reference complex of three-dimensional measurements (coordinate measurements, coordinate increments) has been developed and studied. The means and methods for transmitting a unit of length are presented, as well as the metrological characteristics of the GET 199-2024 in the mode of measuring coordinate increments (length). The sources of non-excluded systematic error and the standard deviation of the measurement result are determined.  As a result of the research performed, it became possible to reproduce a unit of length in the mode of measuring coordinate increments in the range of 0–60 m with a standard deviation of no more than 25 μm for 10 independent measurements and a non-excluded systematic error (with a confidence probability of 0.99) of 19 μm. The functionality of the GET 199-2024 will allow solving current problems of metrological support for high-precision electronic total stations and their analogues in three-dimensional measurement mode.