Analysis of the time-reversal operator for planar dipole arrays

Tortel et al. (1999) analyzed the electromagnetic time-reversal operator for sources and receivers in a ring surrounding a number of dielectric and conducting spheres and cylinders. We analyze the TRO for a planar array and show that for point scatterers there can be up to six eigenvalues and eigenvectors of the time-reversal operator associated with each scatterer. These are associated with various configurations of the induced dipole moments in the scatterer, and depend not only on the geometry but also the polarization capability of the array.