Application of satellite techniques in geodesy and navigation in Poland

Contemporary geodesy is of global dimension. The reference frame is defined as the geocentric system with parameters related to the entire Earth body, e.g. the axis of rotation, and global geoid. The unified time scale is determined for the whole Earth territory as well. International services using different satellite techniques are engaged in the determination of this frame. Particularly important is the Global Positioning System GPS, which is the most important geodetic tool nowadays. In Poland a number of geodetic observatories are working in the frame of the international networks, Polish scientific groups contribute to the advancement of science in this domain. For the practical applications we are using the local networks that again are constructed with satellite techniques. In Europe the regional network EUREF exists while its part EUREF-POL and densification POLREF are in Poland. The modern network ASG-EUPOS is under construction. The GPS technique is used for surveying and navigation and for the positioning in motion, which is in-between the preceding traditional methods. Differential augmentation methods are designed to improve GPS signals such as DGPS and EGNOS. The new European satellite navigation system Galileo is in development. Poland is a member and coowner of this system. A number of Polish research institutions are working on new methods of the practical application of GNSS