Sub-space spatial spectrum estimation resolving multiple targets situated within the same conventional Rayleigh diffraction beamwidth.
By decomposing spatial covariance matrices into orthogonal signal and noise subspaces, MUSIC achieves angle-of-arrival angular resolution down to 0.1 degrees, shattering classical Rayleigh beamwidth diffraction limits.
Real-world antenna array mutual coupling distorts spatial steering vectors. Continuous background calibration routines estimate coupling matrices online, preserving sub-space orthogonality across temperature swings.