Procedure for refinement of the height component in Real-Time Kinematic GNSS

Abstract The Real-Time Kinematic (RTK) method of Global Navigation Satellite Systems (GNSS) technology allows the position of points to be determined with centimeter accuracy. The vertical component of the position is determined less accurately than the horizontal component. Two cases were analyzed to ensure higher accuracy of the vertical component on a set of test measurements obtained using 11 GNSS receivers under different observation conditions, at different times of day, with different vector lengths, and different averaging lengths. In the first case, it was found that if the maximum elevation angle – the elevation angle of the satellite closest to the zenith – is greater than 70°, better accuracy of the vertical component is achieved for most of the tested GNSS receivers. In the second case, it was found that averaging measurements at three specified times of day – 6 a.m., 3 p.m., and 9 p.m. – ensures greater accuracy of the vertical component, whose unit mean error is 21 % lower than the unit mean error of a single height measurement. The accuracy of the final average of three measurements is 54 % higher than the accuracy of a single measurement.