The authors consider the impact of a small but nonzero bandwidth on narrowb
and direction-of-arrival (DOA) estimation using an array of sensors. They d
erive expressions for the DBA error for three commonly used array processin
g algorithms: MUSIC, ESPRIT and weighted subpace fitting (WSF). The err-or
expressions are found by a perturbation analysis of these algorithms for sm
all relative bandwidths of the sources. The perturbation-based error predic
tions are compared to the exact deviation for some special cases of interes
t.