An Analytic Formulation of the Doppler VOR Multipath Error for a Digital Receiver -Comparaisons with the Odunaiya Expression

International audienceThe implementation of wind turbines close to VHF Omnidirectional Range (VOR) systems is an importantconcern for civil aviation. The wind turbines constitute a source of multipath that can yield bearing errors inthe azimuth estimated by aircraft receivers.In this context, we have developed a digital receiver including ltering and demodulation responses to takeinto account the dynamic eects of multipaths [1]. In the literature, the bearing error is computed from themultipath characteristics by means of the analytic expression proposed by Odunaiya and Quinet [2]. Theproposed model has been confronted with Odunaiya expression. It has been observed that the digital receiverresponse does not follow the Odunayia expression in presence of a Dopppler VOR signal even in a staticconfiguration.We develop and validate an alternative expression consistent with the receiver. More generally, this questionsthe validity of the Odunayia expression for Doppler VOR signal. Thus, this analytic formulation is confrontedto the one of Odunaiya and tested for realistic scenarios. A parametric study of the multipath parametersto calculate the bearing error by the two expressions is presented. In the literature, the multipath eect onthe REF signal is assumed to be neglected for the Doppler VOR signal. Thus, a study is done to verify thishypothesis