TThe development of surveying instruments in surveying has led to the rapid gathering of measurements on the field. Mostly, these instruments are electronic devices that, in addition to measuring sensors, include processing and memory units. Therefore, when working with surveying instruments we actually operate whit something close to a computer, which allows us to convert measured values into final results in the field. With electronic tachymeters, in the polar measurement process, we measure polar quantities to individual points: horizontal directions, zenith angles and slope distances. With the conversion in the instrument, we obtain and simultaneously export the “measured” coordinates of the points. The accuracy of the coordinates measured with the selected tachymeter is verified by the standardized procedure prescribed by the International Organization for Standardization – ISO. It was for the purpose of determining the accuracy of tachymeters in determining the coordinates of points, the standardised procedure or standard ISO 17123-5 was developed.
The document which outlines the standard ISO 17123-5:2018 prescribes the field measurement and calculation procedure that is used to determine and evaluate the precision of coordinate measurements using an electronic tachymeter as well as other required accessories. The process is configured in such a way that it allows the testing of any electronic tachymeter, and minimizes the impact of the atmosphere.
In the graduation thesis, we performed two field tests; a simplified and full test. Each experiment was performed in two ways: with and without (i.g. manually) the use of automatic target sighting and measuring. We tried to follow the rules of the standardized procedure to a greater extent and finally determined the precision of the measured coordinates. The empirically determined standard deviation was, in the statistical testing process, compared to the precision provided by the instrument manufacturer. We also considered all the additional influences that affect accuracy to ultimately determine the real accuracy of the coordinates of polar measured points.
|