Patent ID: 8633854
Filing Date: 2014-01-21
Classification: G01S

Abstract:
1. A method of determining antenna orientation, comprising: A. providing two or more GNSS signal antennas at known separations from neighboring antennas and at an unknown orientation; B. tracking common GNSS carrier signals simultaneously at the antennas; C. making carrier phase measurements of GNSS satellite signals at the antennas and differencing the carrier phase measurements from all or selected pairs of antennas to form raw carrier phase differences; D. using the raw carrier phase differences to compute an approximate orientation of the antennas; E. determining angles of incidence of incoming GNSS satellite signals with respect to the computed approximate orientation of the antennas; F. using the angles of incidence to index into and obtain phase difference error correction values associated with respective pairs of antennas from an associated lookup mechanism consisting of one or more associated phase error correction maps, lookup tables and models; G. adjusting the raw carrier phase differences using the phase error correction values obtained from the lookup mechanism; H. computing a corrected orientation of the antennas using the adjusted phase differences; I. determining whether the difference between the calculated orientation of the antennas and the corrected orientation of the antennas is larger than a pre-determined threshold, and if the difference is larger, using the corrected orientation as the calculated orientation and determining angles of incidence of incoming GNSS satellite signals with respect to the calculated orientation of the antennas and repeating steps (F) through (I) until the difference is no longer larger than the threshold.