The Least Squares Method Application for the Two-Dimensional Interpolation in Radiation Pattern Measurements

Abstract

The Global Navigation Satellite System spacecraft signal power received at the Earth’s surface is one of the main signal parameters. The navigation signals power measurements have been carried on using a specialized metrological measuring complex based on the large-aperture dish antennas. It is necessary to measure radiation pattern of the spacecraft antenna to estimate signal power at an arbitrary point on the earth’s surface. A description of spacecraft antenna amplitude radiation pattern shape reconstructing based on the two large-aperture antennas observation results is given. The least squares method application in estimating the parameters of the navigation spacecraft antenna amplitude radiation pattern is considered. The amplitude radiation pattern is estimated from the ground-based measurements results of the satellite signals energy characteristics using a special complex based on the large-aperture dish antenna. The method of radial basis functions is used for pattern interpolation. Theoretical and experimental results are presented, the interpolation accuracy is estimated. Examples of amplitude radiation patterns reconstruction by piecewise linear approximation method and radial-basis functions (two-dimensional interpolation) are shown.