The use of Continuously Operating Reference Stations, both singly and as part of an active network, is widely employed in surveying, engineering and other geomatics applications, achieving high accuracy positioning even in real time. With an active network the measurements of the reference stations are processed jointly in order to model the errors and compute network RTK corrections. Due to distance dependent errors (ionospheric and tropospheric delays), single base RTK positioning accuracy decreases with increased baseline length. However, the network solution (NRTK) retains the accuracy and the time to fix ambiguities (TTFA) at a constant level. This study aims to contribute to the scientific research on real time positioning based on active networks. In Southern Spain, ERGNSS, a national CORS network that provides GNSS data for post-processing and real time single- b ased reference station corrections, shares territory with the Andalusian Positioning Network (RAP), a local active network. RAP provides network an d single-based RTK corrections. In order to analyze the quality of real time positioning based on both networks, several tests have been performed on a sample of test points. The reference frame, the time to fix ambiguity resolution, precision, accuracy and repeatability of RTK positioning are considered as the evaluation parameters. The results confirm that the RAP network complements the precise positioning services provided by the ERGNSS network, ensuring accurate real time positioning, full cove rage and reliable positioning services in the Andalusian Community., Mª Selmira Garrido, Antonio J. Gil and Rafael Gaitán., and Obsahuje bibliografické odkazy
A modern seismological network with telemetric data transfer has been constructed in southern Bohemia. The network is made up of 5 stations equipped with Reftek DAS (Data Acquistion System) 130-01 Broadband Seismic Recorders and GeoSIG VE-53 triaxial velocity sensors with a natural frequency of 1 Hz. The network works at a sample rate of 250 Hz. The main purpose of this network is to monitor local seismicity in southern Bohemia with a special focus on seismic activity in the vicinity of the Temelin NPP. The sensitivity in the central part of the network is at least 0.0 ML. In addition to monitoring local tectonic movements it also monitors the effects of Alpine earthquakes in the area of southern Bohemia. For this reason one of the sites on the network is equipped with a GeoSIG AC-63 triaxial force balanced accelerometer., Vladimír Nehybka, Romana Hanžlová, Jan Otruba, Jan Švancara and Radim Vlach., and Obsahuje bibliografické odkazy