In the phase A, the C.A.. has the responsibility of developing an infrastructure able to acquire and process signals coming from 4 pseudolites, from GPS, from EGNOS and from the GSTB V2 experimental satellite and able to support the testing of applications demanding high accuracy positioning providing augmentation to the users in the covered area. During Phase A, the GTR will achieve a basic configuration, called “start-up” and its main objectives are: To provide a preliminary validation of the whole set of pseudolites implemented from this first stage, eventually in combination with the reception of the satellite GSTB-V2 that is already in orbit from the beginning of 2006, waiting for the Galileo signal. To carry out analysis and experimentation on the GPS, EGNOS e GSTB-V2 signals (the latter at least for the frequency in the L1 band) that bring to the evaluation of their navigation performance, through the suitable acquisition, filing and processing of the gathered data. The characterization of the environment, by means of the use of an appropriate meteo station foreseen in the GTR architecture.(Figure 1) The physical realization of a local time reference, through the development and implemantation of a time laboratory within the GTR. The implementation of local “augmentation” of the navigation performance for the development of applications prototypes based on the use of navigation GPS+EGNOS signals. The Phase A architecture has been designed taking into account the mentioned technical requirements and it is composed by the following macro segments:
 Figure 1 GTR final high level architecture III. THE ANALYSIS & CONTROL CENTER The characterization of the Galileo signal, with the consequent evaluation of the navigation performance in relation to its more prominent design aspects, such as the modulation and coding scheme it adopts, cannot leave out of consideration special calculation infrastructures. From the above follows the identification of a certain number of laboratories (for the generation of the time, the computation and analysis of orbitography and integrity) that the GTR requires in its configuration to be able to process and file the navigation data gathered with suitable Galileo receivers (available on site). The Analysis & Control Center, the heart of the GTR, is composed by a Control Centre, Processing Facilities and Specialised Laboratories, and it is sited in the Tecnopolo Area (in the East of Rome). It includes the structures dedicated to the processing of the navigation data produced in the experimental area. It includes the Signal Generator (SGF), that provides a controlled environment for User Terminal Qualification Tests. The Analysis & Control Center includes moreover the Time Laboratory (TLF), used to provide a reference time scale to the GTR system. This laboratory is composed by a group of high stability atomic clocks (one H-Maser and four Caesium atomic clocks) operating in a controlled environment. This guarantees a high stability both at short term and at medium/long term; the GTR-ST time scale is moreover synchronized to the TAI by means of GPS System Time. The Integrity (ILF) and Orbitography (OLF) Laboratory facilities provide the support for the implementation of the integrity and navigation algorithms both on the GPS and Galileo constellation and on the pseudolite constellation. Two types of processing chains are implemented in the GTR:
 Figure 2 Sycronization concept Finally the Control Center contains the infrastructures for the monitoring and control of all the GTR elements besides the filing center of all the data produced by it. Moreover the general purpose GTR-Laboratory has all the instruments necessary to support more innovative studies and activities, such as analysis, modelling and compensation of errors affecting GPS and Galileo measurements, development of Galileo Receivers technology, development of prototype applications and certification (with focus on the applications certification). |