Glidepath

Glide slope / Glide Path

Is a portion of the ILS that provides the pilot with vertical guidance to the touchdown point of the runway. The GP generates an RF−Signal at frequency range of 328 to 336 MHz and is amplitude modulated with 90 and 150 Hz. The transmitter of GP can be a 2F system or 1F system and both produce 5 W of power. The glide path signal is receivable up to a distance of 10 nautical miles within an azimuthal sector of ±8°relative to the localizer course line with the touch down point as reference and between the elevations 0.30 to 1.75 nominal glide path angle.The GP antenna is installed approximately 286 to 344 m beyond the runway threshold and 120 to180m from the runway centre line. An optional nearfield dipole is installed in the GP radiation sector for monitoring the course position of the GP signal. The position of the dipole depends on the type of installation and on the local conditions as regards the glide angle. The GP transmitter shelter is installed in the vicinity of the GP antenna.

Glidepath or Glideslope also radiates two modulating signal, the 90Hz and 150 Hz. Above the path angle 90Hz is predominant than 150Hz. Below, the 150Hz is predominant than 90Hz, and at path angle the two are equal.