An optimum inversion method for the remote probing of defective phase shifters in phased arrays

The "best-linear estimate" method for the solution of improperly-posed inverse problems is applied to the remote sensing of defective phase shifters in phased arrays. The experimental data, obtained by measuring a field component in the Fresnel region, are inverted using a matrix operator which is determined taking full advantage of all the available statistical informations on the quantities to be detected and on the error sources affecting the measurements. Numerical simulations, concerning a rectangular array of dipoles scanned in elevation, demonstrate the superiority of the statistical method with respect to other inversion procedures proposed for this application.