A random-signal approach to robust radar detection

The paper presents a novel family of robust radar receivers for the problem of detecting the possible presence of a coherent return from a given cell under test. The idea is to introduce a random signal in addition to the nominal steering vector, with a given structure, but whose entity is estimated from the data (hence can also be zero). While in the classical formulation the target signature is present only in the mean of the likelihood function, and recent work investigated tests based on the sole covariance matrix, the proposed approach splits the target signature between mean and covariance. In particular, the complex amplitude is modeled as an unknown deterministic parameter while the random part of the signature is included in the covariance to promote robustness. Preliminary results for different choices of the design matrix (that is, of the structure of the covariance matrix of the random signal) show that a palette of behaviors can be obtained, with different trade-offs between loss under matched conditions and robustness to mismatches.