An adaptive spatial filter estimate of the source moment is given by sˆr,t=wTrbt, where w(r) is the weight vector. The weight vector w(r) of an adaptive spatial filter called the array-gain constraint minimum variance scalar beamformer is calculated by minimizing wT(r)Rw(r) subject to lTrwr=lr. The solution is known to be [46]: wr=R−1l˜rl˜TrR−1l˜r
