“…In the tessarine domain, two types of properness have recently been introduced, namely T 1 and T 2 -properness [24,32], and they have been satisfactorily applied in multisensor fusion estimation problems with uncertainties in the measurements [22,23]. In [22], T k -proper, k = 1, 2, centralized fusion algorithms of reduced dimension are proposed for the computation of the optimal (in the least-squares sense) filter, predictor, and fixedpoint smoother of the state in systems with random one-step delays and correlated noises.…”