an ILS (instrument landing system) navigation facility in the terminal area navigation system located approximately 3500 ft from the runway approach end on the extended centerline, transmitting a 75 MHz fan-shaped radiation pattern, modulated at 1300 Hz
Это интересно
It is keyed alternately dot and dash and received by compatible airborne equipment, indicating to the pilot both aurally and visually, that he or she is passing over the facility. The middle marker is located at or near the point of decision height for ILS Cat I.
Это интересно
Valdkond ICAO lisade põhjal loodud klassifikaatori järgi: Lennundusside (telekommunikatsioon)
Keskmarker asub tavaliselt raja lähedal otsusekõrguse punktis, kus glissaadi kõrgus maapinnast on umbes 200 jalga. Keskmarkeri signaal koosneb punktidest ja kriipsudest sagedusel 1300 Hz, 6 märki sekundis ja sünkroonselt vilgub oranž lamp.
A middle marker beacon is also used. It is located on approach approximately 3,500 feet from the runway. It also transmits at 75 MHz. The middle marker transmission is modulated with a 1300 Hz tone that is a series of dots and dashes so as to not be confused with the all dash tone of the outer marker.
