DSCa	difference and sum co-array
DOF	degree of freedom
NA	nested array
DsNA	diff-sum nested array
ULA	uniform linear array
DOA	direction of arrival
DCa	difference co-array
CA	coprime array
ANA	augmented nested array
VCAM	Vectorized Conjugate Augmented MUSIC
SS MUSIC	spatial smoothing based MUSIC
KR	Khatri–Rao
RMSE	root mean square error