Method and apparatus for radio location

A method for determining the azimuth and elevation angles of the direction of arrival of a travelling signal wavefront of measurable wavelength, .lambda., comprising the steps of:

• utilizing an array of discrete sensor elements arranged with nonuniform spacing around a circle;
• taking a phasor-difference between the outputs of pairs of spaced elements, said phasor-difference being a function of the azimuth and elevation angles of arrival of said travelling signal wavefront;
• and
• deriving from said phasor-difference the azimuth and elevation angles of the direction of propagation of said signal wavefront relative to angle references associated with said array.

A method for determining the azimuth and elevation angles of the direction of arrival of a travelling signal wavefront of measurable wavelength, .lambda., comprising the steps of:

• utilizing an array of discrete sensor elements, some of which arranged along an arc of a conic section, others of which are arranged off of the conic section;
• taking a phasor-difference between the outputs of pairs of spaced elements;
• and
• deriving from said phasor-difference the azimuth and elevation angles of the direction of propagation of said signal wavefront relative to angle references associated with said array.

An apparatus for determining the azimuth and elevation angles of the direction of arrival of a travelling signal wavefront of measurable wavelength, .lambda., comprising:

• an array of discrete sensor elements, some of which arranged along an arc of a conic section, others of which are arranged off the conic section;
• means for taking a phasor-difference between the outputs of pairs of spaced elements;
• and
• means for deriving from said phasor-difference the azimuth and elevation angles of the direction of propagation of said signal wavefront relative to angle references associated with said array.

A method for determining the azimuth and/or elevation angle(s) of the direction of arrival of a travelling signal wavefront of measurable wavelength, .lambda., comprising the steps of:

• utilizing any of a multiplicity of planar arrays of discrete sensor elements with a linear dimension, or separation, between at least two elements, that exceeds 1.22.lambda.;
• taking a phasor-difference between the outputs of pairs of spaced elements to produce a set of phasor differences;
• transforming said set of phasor differences into a resultant three-dimensional vector pointing in a direction of propagation of said signal wavefront;
• identifying the azimuth and elevation angles of arrival of the signal wavefront relative to an angle reference system associated with any of said multiplicity of planar arrays.

A method for determining the azimuth and/or elevation angle(s) of the direction of arrival of a travelling signal wavefront of measurable wavelength, .lambda., comprising the steps of:

• utilizing a two-dimensional, circular array of discrete sensor elements with a linear dimension, or separation, between at least two elements, that exceeds 1.22.lambda.;
• taking a phasor-difference between the outputs of pairs of spaced elements to produce a set of phasor differences;
• transforming said set of phasor differences into a resultant three-dimensional vector pointing in a direction of propagation of said signal wavefront:
• identifying the azimuth and elevation angles of arrival of the signal wavefront relative to an angle reference system associated with said array, said step of transforming further including the steps of:
• deriving from said set of phasor differences a resultant East-West and a resultant North-South phasor;
• and
• combining said resultant East-West and North-South phasors to derive an azimuth of the direction of propagation of said signal wavefront relative to a reference North-South direction, and/or an elevation of angle of the direction of propagation relative to a reference plane associated with said array.