Multichannel detection of Gaussian signals with uncalibrated receivers

We consider the detection of unknown Gaussian signals received by an array of uncalibrated nonidentical sensors, which is a problem that appears in radio astronomy. The problem is formulated as a test on the covariance structure. The generalized likelihood ratio test (GLRT) for this problem is stated and related to a simpler ad-hoc detector. We compare the method to the conventional multichannel subspace detector and show its robustness to nonidentical channels on data collected with the Westerbork radio telescope.