Analysis of the adaptive matched filter algorithm for cases with mismatched clutter statistics

In practical radar applications of the adaptive matched filter algorithm, the covariance matrix for the clutter-plus-noise is typically estimated using data taken from range cells surrounding the cell under test. In a nonhomogeneous environment, this can lead to a mismatch between the mean of the estimated covariance matrix and the true covariance matrix for the range cell under test. Closed form expressions are provided, which give the performance for such cases. These equations are exact in some cases and provide useful approximate results in others. Performance depends on a small number of important parameters. These parameters describe which types of mismatches are important and which are not. Numerical examples illustrate how the performance varies with each of the important parameters. Monte Carlo simulations are included which closely match the predictions of our equations.