Descrizione

Key Facts The R&S®EVS-K9 and R&S®EVS-K10 software options make it possible to test the VHF data link (VDL) of GBAS and SCAT ground-based satellite navigation systems. The content of all GBAS/SCAT timeslots (A to H) is analyzed and synchronized using an external GPS receiver (1 pps signal). For each timeslot, the instrument lists the main parameters (slot and station ID, transmission length, message ID, FEC and repetition rate) along with the frequency offset and level measured for the signal under test. In the slot view, operators can visualize the individual messages (up to eight) carried in a specific slot, together with the message type and message length. For both GBAS and SCAT signals, the instrument delivers a detailed analysis of type 1 messages, which contain the GPS correction data (satellite information and pseudorange corrections) for the multimode receivers on board the aircraft, as well as of type 4 messages, which contain, in their final approach segment data block (FASDB), all the data required to provide precision approach and landing. All measured values and data contents can be logged, saved and exported via a USB stick using the instrument's data logger. The data logger also enables plausibility checks on GBAS/SCAT systems by graphically displaying the GPS position error with respect to a reference position and the pseudorange correction data in a single chart.
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