This paper proposes a solution to the problem of synthesizing distributed decentralized estimators for a formation of agents. The collected dynamics of the formation are modeled by a discrete LTI system. In the considered estimation structure, each agent of the formation carries an estimate of the entire formation state. Agents of the formation can communicate information between each other through unidirectional links modeled with a fixed or a stochastic communication topology. The design procedures are based on a set of convex optimization problems with linear matrix inequalities and result in the suboptimal choice of estimator gains which stabilize the estimation error dynamics and minimize a norm of the estimation error correlation matrix. (C) 2009 Elsevier Ltd. All rights reserved.