IMPROVEMENT OF VERIFICATION METHODS FOR TOTAL STATIONS BY COMPARISON WITHOUT A COMPARATOR

Abstract

In order to ensure the uniformity of geodetic measurements it is necessary, in accordance with the requirements of the respective local verification schemes, to perform verification of the used instruments, which include total stations, at certain intervals. According to this scheme, total stations can be calibrated using the direct measurement method with the use of BP-1 basing devices as well as the comparison method with the use of high-precision phased light-dial meters (total stations). Nowadays the periodic metrological verification is fulfilled only by direct measurements with the application of stationary reference linear bases of the 2nd and 3rd categories that in their turn are also verified with the use of basic instrument BI-1. At the same time it should be noted that there are considerable difficulties in implementing the direct measurement method because a significant number of these bases have been lost. For example, only 2-3 bases for the whole territory of the Russian Federation are currently in proper condition. This leads to the fact that, in order to perform metrological verification on these bases, total stations must be transported over considerable distances.

This has raised the scientific and technical challenge of developing methods of verifying total stations without the use of reference bases. These methods are based on the method of comparison without a comparator. The advantage of these methods is that it is not necessary to create and maintain stationary linear bases.

In the article the suggested methods of verification are based on simultaneous measurement of arbitrarily chosen distances by the reference and verifiable total stations followed by comparison of the results. Afterwards the differences between the measured distances of the reference and verifiable total stations are calculated and the accuracy of the verifiable total station is evaluated.