Estimating the directions of arrival (DOAs) of propagating planewaves is a requirement ina variety of
applications including radar, mobile communications, sonar, and seismology. Due to its simplicity
and high-resolution capability, ESPRIT (Estimation of Signal Parameters via Rotational Invariance
Techniques)  has become one of the most popular signal subspace-basedDOAor spatial frequency
estimation schemes. ESPRIT is explicitly premised on a point source model for the sources and
is restricted to use with array geometries that exhibit so-called invariances ....