Method and apparatus for ambiguity resolution in a rotating interferometer wheel

Claim 1

A method of determining angle of arrival of signals at a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, said method comprising the steps of: (a) receiving signals at multiple roll angles of the interferometer wheel; (b) measuring frequency and phase differences of signals received at the multiple roll positions of the interferometer; (c) determining a set of conic angle intersections based on the measured phase difference at each of the multiple roll positions; (d) determining a set of azimuth and elevation angles based on the set of conic angle intersections; and (e) assigning as the angle of arrival an azimuth and elevation to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 2

A method of determining angle of arrival of signals at a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, said method comprising the steps of: (a) receiving signals at multiple roll angles of the interferometer wheel; (b) measuring frequency and phase differences of signals received at the multiple roll positions of the interferometer; (c) determining a set of conic angle intersections based on the measured phase difference at each of the multiple roll positions; (d) determining a set of azimuth and elevation angles based on the set of conic angle intersections; and (e) assigning as the angle of arrival an azimuth and elevation to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 4

An apparatus for ambiguity resolution in a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, comprising: means for measuring, at multiple roll positions of the interferometer about the axis, frequency and phase differences of signals received by the interferometer; means for determining groups of conic line intersections for each set of conic lines using one conic lines from each ambiguous phase measurement; means for determining azimuth and elevation proximity for each group of conic line intersections; and means for assigning as an angle of arrival an azimuth angle and an elevation angle to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 5

An apparatus for ambiguity resolution in a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, comprising: means for measuring, at multiple roll positions of the interferometer about the axis, frequency and phase differences of signals received by the interferometer; means for determining groups of conic line intersections for each set of conic lines using one conic lines from each ambiguous phase measurement; means for determining azimuth and elevation proximity for each group of conic line intersections; and means for assigning as an angle of arrival an azimuth angle and an elevation angle to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 6

A method of determining angle of arrival of signals at a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, said method comprising the steps of: (a) receiving signals at multiple roll angles of the interferometer wheel; (b) measuring frequency and phase differences of signals received at the multiple roll positions of the interferometer; (c) determining a set of conic angle intersections based on the measured phase difference at each of the multiple roll positions; (d) calculating a set of possible unambiguous phase differences which could have yielded ambiguous measured phase differences for each of the multiple roll positions of the interferometer about the axis of rotation; (e) determining the set of conic angles based on the set of calculated phase differences; (f) determining a set of azimuth and elevation angles based on the set of conic angle intersections; and (g) assigning as the angle of arrival an azimuth and elevation to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 7

A method of determining angle of arrival of signals at a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, said method comprising the steps of: (a) receiving signals at multiple roll angles of the interferometer wheel; (b) measuring frequency and phase differences of signals received at the multiple roll positions of the interferometer; (c) determining a set of conic angle intersections based on the measured phase difference at each of the multiple roll positions; (d) calculating a set of possible unambiguous phase differences which could have yielded ambiguous measured phase differences for each of the multiple roll positions of the interferometer about the axis of rotation; (e) determining the set of conic angles based on the set of calculated phase differences; (f) determining a set of azimuth and elevation angles based on the set of conic angle intersections; and (g) assigning as the angle of arrival an azimuth and elevation to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 8

An apparatus for ambiguity resolution in a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, comprising: means for measuring, at multiple roll positions of the interferometer about the axis, frequency and phase differences of signals received by the interferometer; means for determining groups of conic line intersections for each set of conic lines using one conic lines from each ambiguous phase measurement; means for calculating a set of possible unambiguous phase differences which could have yielded ambiguous measured phase differences for each of the multiple roll positions of the interferometer about the axis of rotation; means for determining the set of conic angles based on the set of calculated phase differences; means for determining azimuth and elevation proximity for each group of conic line intersections; and means for assigning as an angle of arrival an azimuth angle and an elevation angle to a group of conic lines, one from each phase measurement, which are nearest each other.

Claim 9

An apparatus for ambiguity resolution in a rotating interferometer wheel having a boresight and rotating about an axis parallel to the boresight, comprising: means for measuring, at multiple roll positions of the interferometer about the axis, frequency and phase differences of signals received by the interferometer; means for determining groups of conic line intersections for each set of conic lines using one conic lines from each ambiguous phase measurement; means for calculating a set of possible unambiguous phase differences which could have yielded ambiguous measured phase differences for each of the multiple roll positions of the interferometer about the axis of rotation; means for determining the set of conic angles based on the set of calculated phase differences; means for determining azimuth and elevation proximity for each group of conic line intersections; and means for assigning as an angle of arrival an azimuth angle and an elevation angle to a group of conic lines, one from each phase measurement, which are nearest each other.