Direction of arrival using Root MUSIC

estimates
the directions of arrival, `ang`

= rootmusicdoa(`R`

,`nsig`

)`ang`

, of a set of plane
waves received on a uniform line array (ULA). The estimation uses
the *root MUSIC* algorithm. The input arguments
are the estimated spatial covariance matrix between sensor elements, `R`

,
and the number of arriving signals, `nsig`

. In
this syntax, sensor elements are spaced one-half wavelength apart.

[1] Van Trees, H.L. *Optimum Array
Processing*. New York: Wiley-Interscience, 2002.