Dr inż. Marek Plewako

The effect of prolonged measuring time on accuracy of point position fixed with RTK GPS technique in asg-eupos system

The paper deals with effects of prolonged measuring time of observation in case of fixing single point position with RTK GPS in co-operatin with active geodetic network ASG-EUPOS. The conclusions are based on 2 independent research works done specially to solve this problem.Both investigations show clear dependence between the time of measurement and the accuracy of positioning in case of single reference ASG-EUPOS station at the distance less than 5 km.For distances longer than 10 km; when the impact of distance dependent errors prevails, it is not recommended to extend measuring time over 10 seconds.Further investigations should be done to show more precisely to what extend (between 5 and 10 km) is it worth to extend the time of measurement. ...

Dr inż. Marek Plewako

Researching the accuracy of hand held GPS receivers

Analysing the results of determining x, y coordinates of a single point posi-tion by GPS hand held receiver leads to find out a systematic component. It exists for different types of receivers, in different provinces, in different reference systems. Elimination of this bias from the set of observations makes it possible to diminish true values of errors of determination of point location.There are some other different sources of errors in determination of point location: number of satellites in view, quality of their geometry (PDOP), using EGNOS system, multipath errors and also observation time at the station.Researching the latter error it was found out, that reliable results are opta-inable after 2 minutes since the observation started.     ...