Posouzení využitelnost techniky Precise Point Positioning pro mapování

Abstract

The thesis deals with the testing of Precise Point Positioning (PPP) in real-time mode which is a modern technique for positioning using Global Navigation Satellite Systems (GNSS). After gaining a theoretical knowledge about this technique and putting a GNSS equipment into operation, four sets of measurements on the stabilized polygon of ten points was realized using PPP and RTK methods. Obtained coordinates of all points from both techniques were compared and differences between each set of measurements and between the techniques were computed. An average difference between PPP and RTK varied in a position from 0.70 to 1.86 m and in a height from 1.07 to 2.22 m. Measurements realized in open areas with a good visibility of the sky reached better results (smaller differences between the techniques) than measurements in urban areas where obstacles lowered the number of visible satellites. Reached accuracy limits the use of PPP technique working in real-time mode only to applications where very high accuracy is not required. Disadvantage of the PPP method is also an occasionally instability of correction satellites ephemeris and satellite clock streams produced by IGS (IGS real-time products). On the other since the PPP is not dependent on differencing of observations and therefore requires no GNSS reference stations, it makes it a very interesting option for some applications.