Study On The Influence Of Multipath Effect On The Localizer System Based On The Echo Model

Since the advent of aircraft, flight take off and landing are the most critical partsin the whole process stage. According to statistics, after the airlines founded, thenumber of air accidents continue to grow. Especially in the landing part, the majoraccident occurred at this stage. How to use navigation equipment to insure the aircraftto have a safely environment at night and the poor weather conditions is a veryimportant subject. Discussed ILS in this paper means M wave instrument landingsystem. Multipath effect the direction of figure of the M wave antenna very much.As one of radio navigation systems for precision approach landing guide, ILScomposed by localizer, glideslope and market beacon. ILS can provide the departureof heading, the departure of the descending and the relative location information forthe landing aircraft. The accuracy of ILS’s navigation information is chiefly decidedby two aspects, one is the ground equipment and airborne equipment workingnormally, the other is the electromagnetic environment surrounding antenna array. Inthis paper researches on the subject only from the process of flight landing approachused by guide way, excluding airport factor,. In the landing stage, The pilot can usevisual approach, NDB approach, VOR/DME approach, skyriver approach etc.Compared the several ways, instrument landing system save more time than the otherways in the landing stage. Because of the instrument landing system approach isprecision approach,the other way is a precision approach, without vertical horizontalguide. Precision approach can have a relatively smaller interval of flight, especiallyunder the poor visibility environment, instrument landing system is indispensable.The deterioration of the electromagnetic environment at airport seriously affectsthe landing guidance. The multipath effect caused by the obstacles surrounding theequipment seriously interferes the airborne instrument. In this paper, localizer issimulated by MATLAB through establishing echo system model. The radio signalsproduced by ILS on ideal environment and the multipath effect which caused byobstacles surrounding the ILS equipment are analysised. The influence of themultipath effect caused by the obstacles effecting the performance will be known bythe comparison of the DDM of two cases. Finally, give a few suggestions to improvethe impact of multipath effects...