Kelly's generalized likelihood ratio test (GLRT) statistic is reexamin
ed under a broad class of data distributions known as complex multivar
iate elliptically contoured (MEC), which include the complex Gaussian
as a special case. We show that, mathematically, Kelly's GLRT test sta
tistic is again obtained when the data matrix is assumed MEC distribut
ed. The maximum-likelihood (ML) estimate for the signal parameters-ali
as the sample-covariance-based (SCB) minimum variance distortionless r
esponse beamformer output and, in general, the SCB linearly constraine
d minimum variance beamformer output-is like,vise shown to be the same
. These results have significant robustness implications to adaptive d
etection/estimation/beamforming in non-Gaussian environments.