The problem of resource management in search and track mode for phased array radars is considered based on covariance control.An optimal model of resource allocation is presented

which selects sensor working mode based on the difference between the desired covariance matrix and that of the actual covariance of each target.Two kinds of resource management algorithms

the minimum mean deviation criterion and the minimax deviation criterion

are proposed

respectively.The proposed algorithms can control sensor working mode between search and track with optimal resources allocation

and keep all targets in the desired states.Simulation results with absolute trace and 2-norm matrix metrics show that the algorithms based on covariance control can effectively allocate sensor resources with the desired tracking state maintained.Finally

the selection of the desired covariance matrix is discussed.