Radar Network Scanning Coordination Based on Ensemble Transform Kalman Filtering Variance Optimization Luther White Department of Mathematics University of Oklahoma Norman, Oklahoma 73019 lwhite@ou.edu and Alan Shapiro School of Meteorology University of Oklahoma Norman,Oklahoma 73019 ashapiro@ou.edu November 28, 2006 Abstract In this work the variance of the error of analyzed wind fields obtained from an ensemble Kalman filter is used as a criterion with which to op- timize radar network scanning strategies. The measurement equation in the Kalman filter approach is obtained from variational wind retrieval and, thus, is a function of the retrieval scanning parameters. It is shown that the mapping from radar parameters to the variance of the error is differentiable. The ensemble transform is introduced to facilitate the com- putational effort. The approach presented in principle may be used to optimize the scanning strategy in a network with any number of radars. Numerical examples are presented with networks consisting of two, four and nine radars using a quasi monte carlo optimization scheme. Error estimates for the approximation of the optimal strategies are discussed. 1. Introduction. The objective of this work is to determine criteria by which cooperative mea- surements may be made from a radar network that in some way maximizes information. The approach is to use Kalman-based filtering procedures that produce not only estimated wind fields but also estimates of the variance of 1