The effect of ionospheric tilt on radio direction finding position estimates

Abstract

It is generally accepted that the ionosphere tilts; that is to say , an isoionic layer is not at constant height above the surface of the earth. Ionospheric tilt has the effect of deflecting a radio ray out of its great­ circle plane and returning it to earth at an angle not that of the true bearing from a receiver to a transmitter. The magnitude of error introduced by this effect on radio direction finding (RDF) position estimates was studied in this paper. A model assigning a tilt bias of less than three degrees to each RDF station bearing was constructed. Analysis of a six-station RDF network revealed that this amount of tilt has negligible effect on point estimates of location and their confidence regions.