| CPC G01S 3/38 (2013.01) | 15 Claims |
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1. A method of tracking a satellite signal source using an antenna, such method comprising:
determining the direction of the antenna to receive a maximum signal level from the satellite during a gathering stage by
rotating an RF axis of the antenna within a single plane through three or more predetermined measurement angles,
measuring a signal level at each angle,
retaining three measured signal levels and corresponding angular positions of the predetermined measurement angles such that the measured signal level at the second angular position exceeds that of both the first and third angular positions,
determining a set of coefficients of a quadratic function that relates the measured signals to the angular positions,
using the coefficients of the quadratic function to determine a first angular position which maximizes a signal level from the signal source,
storing the determined angular position,
and
repeating the preceding steps in an orthogonal plane to provide a second angular position;
periodically performing the foregoing determining the direction of the antenna to receive maximum signal level process to obtain a set of first and second determined angular positions;
submitting the set of angular positions to a Kalman filter to generate a filtered output;
using the filtered output to estimate the position of the satellite.
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