Association of DOA estimation from two ULAs

In this paper, we consider the problem of associating estimated direction-of-arrival (DOA) angles of multiple targets using two uniform linear arrays (ULAs) of sensors. It is categorized as a multisource information aggregation problem, in which we devise our algorithm in the following two steps: 1) Estimate two sets of DOA angles from two ULAs, respectively, and 2) associate estimated DOA angles with the targets. Note, however, that the primary focus of this paper is the second step, i.e., association of DOA angles with the corresponding targets, whereas for the first step, we use the well-known improved polynomial rooting method. Generally speaking, if there are q targets, we have q! possible association pairs, among which, there is only one set corresponding to the correct association. Since target signals must be correlated in the observations of two ULAs, we can determine how to associate the DOA angles computed from step 1 by evaluating the covariance matrix of the data received at the two ULAs. The algorithm is effective, robust, and accurate in classifying the DOA angles into the correct association.