Method of estimating a direction of arrival of an electromagnetic wave at an antenna array

A computer-implemented method of estimating a direction of arrival of an electromagnetic wave at an antenna array, the method comprising:

• estimating a covariance matrix of signals acquired by the antenna array, the signals being derived from the electromagnetic wave,
• calculating a normalised eigenvector of the covariance matrix, the eigenvector being associated with an eigenvalue of the covariance matrix,
• correlating the normalised eigenvector with a first reference table so as to produce a first correlation spectrum comprising correlation indices respectively associated with different directions of arrival, the first reference table comprising normalised responses of the antenna array to a first reference electromagnetic wave polarised in a first direction and respectively associated with different directions of arrival of the first reference electromagnetic wave,
• correlating the normalised eigenvector with a second reference table so as to produce a second correlation spectrum comprising correlation indices respectively associated with different directions of arrival, the second reference table comprising normalised responses of the antenna array to a second reference electromagnetic wave polarised in a second direction respectively associated with different directions of arrival of the second reference electromagnetic wave, the second direction being different from the first direction,
• constructing a third reference table by linear combination of the first reference table and the second reference table, with a polarisation component of the electromagnetic wave in the first direction and with a polarisation component of the electromagnetic wave in the second direction, respectively,
• correlating the normalised eigenvector with the third reference table so as to produce a third correlation spectrum comprising correlation indices associated with different directions of arrival,
• identifying a direction of arrival associated with a maximum correlation index of the third correlation spectrum.