Doppler VOR

Article By:

Kramar, Ernst Formerly, Standard Elektrik Lorenz Aktiengesellschaft, Stuttgart, Germany.

Greenspan, Richard L. The Charles Stark Draper Laboratory, Cambridge, Massachusetts.

Last reviewed:November 2019

DOI:https://doi.org/10.1036/1097-8542.203600

A very high-frequency omnidirectional radio range (VOR) employing the Doppler principle. The bearing accuracy achieved by users when VOR beacons are installed in the vicinity of obstructions, or when aircraft using VOR signals fly over mountainous terrain, is deteriorated by reflections (site and enroute errors). The Doppler VOR solves this problem by two fundamental principles maintaining full compatibility of the radiated information with existing airborne receivers. It uses a wide-base antenna array (Fig. 1) for suppressing the effects of multipath propagation and the Doppler principle for determination of bearing. According to the Federal Radionavigation Plan of 2001, approximately half of the existing VOR stations in the United States will be phased out beginning in 2010. However, Doppler VOR will be installed in those remaining VOR sites where performance is degraded by multipath propagation. See also: VOR (VHF omnidirectional range)

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