Angle of arrival (AOA) estimation using FMCW radar using MUSIC algorithm
Yes, it is proper/practical way to obtain correlation matrix. just multiply your sample with its conjugate to get auto-correlation and with conjugate of other antenna elements sample to get cross-correlation. arrange them in matrix to get correlation matrix($N$$X$$N$).
you can also look out for MVDR implementations in matlab which uses similar method for obtaining noise correlation matrix.