Scattering error in a radio interferometer

Scattering error in an interferometer-angle-measuring system is investigated theoretically and numerically. The model employed consists of four identical base-loaded vertical antennas erected at the corners of a square. The assumption is made that the earth is a perfectly conducting plane of infinite extent. Curves are supplied for the error angle as a function of antenna spacing, with azimuth angle of wave arrival as parameter. The incident electric field is vertically polarized. These data were computed for quarter-wave vertical elements having a length-to-radius ratio of 122.35 and for base-load resistors of 12.5, 50, 200 and 500 ohms. A brief résumé of the theory of the two-element ratio interferometer is presented, together with a numerical analysis when quarter-wave antennas are employed having a length-to-radius ratio of 74.21 and for the same values of base loads.