Билет №42
1). INTERROGATOR. The ground-based transmitter which is known as the INTERROGATOR transmits on 1030MHz. The interrogator pulses from the ground can be radiated from a directional SSR aerial mounted on the primary radar aerial. The transponder is interrogated every time the radar scans the aircraft
2). Typical SSR Operation:
The pilot selects an identification code.
The SSR ground transmitter sends a coded interrogation signal on 1030MHz as the primary radar system detect the aircraft. This coded signal is in the form of pairs of pulses and the spacing of the pulses in each pair determines the MODE of the interrogation.
The interrogation signal is received, detected and decoded by the airborne transponder.
The airborne transponder encodes and transmits a set of reply signals, depending upon mode and code selected.
The reply signal is then received, decoded and displayed at the ATC unit.
3). At what Frequency operate ILS. ILS is a runway approach aid providing lateral(localizer) and vertical(glideslope) guidance that allows aircraft to safely approach the runway from several miles out. Localizer transmit in the VHF band on frequencies between 108 and 112MHz. Glide Slope transmissions are in the UHF band on frequencies between 329 and 335MHz.