Diploma thesis deals with the procedure of the internal JAVAD TRIUMPH-LS antenna's calibration verification. We wanted to check whether the 2,5 cm nozzle is included in the initial NGS antenna calibration. The verification procedure has been performed on the roof of the faculty's building, where the instruments were set on three pillars; we have used one JAVAD TRIUMPH-LS instrument, the rest of the instruments were from other manufactures. In the static observation processing antenna height from the instrument JAVAD TRIUMPHLS has not been taken into account in order to get a deviation from the reference value. We came to the conclusion that in the initial calibration of the instrument adapter is not included and that we need to measure the height of the antenna to the labels on the instrument. Further we have verified the quality of coordinates, gathered from RTK-positioning using JAVAD TRIUMPH-LS additional accessories based on inclinometer. While using RTKmethod we have acquired coordinates when the instrument was inclined to 15°, 30° and 45° angles. We have found such positioning might be problematic, since already by 15° we have obtained deviations about 10 cm in each horizontal component. Therefore, when using the instrument JAVAD TRIUMPH-LS to determine the RTK-positions the slope of the instrument from the vertical should not be above of 15° inclination or even better in order to achieve best quality positioning results using rectified labels is more appropriate.