  This paper describes a state estimation approach for non-causal time-varying
linear descriptor equations with uncertain parameters. The uncertainty in the
state equation and in the measurements is supposed to admit a set-membership
description. The approach is based on the notion of the linear minimax
estimation. Suboptimal minimax state estimation algorithm is introduced for
DAEs with non-stationary rectangular matrices. Optimal algorithm is presented
for DAEs with special structure of the matrices. A comparison of suboptimal and
optimal algorithms is presented for 2D time-varying DAE with a singular matrix
pencil.
