Two-frequency glidepath transmitter station for the standardised instrument landing system ILS

摘要

The transmitting station includes antenna beam groups (A1-A3) from which signals (KS1-KS3) are selected (AS) for processing by an I/Q converter. Real and imaginary parts of the modulation frequencies are subjected to a Fourier transform and combined in the frequency plane with directed values for ground-reflected components of the transmitted signals. The actual far-field equivalent signals are compared with stored desired values. If the discrepancy exceeds a tolerable limit the installation is reconfigured or switched out.