<FONT face=Verdana>This paper assesses the performance of range-spread target detector in spherically invariant random vector clutter

when the actual signal is misaligned with the assumed direction of arrival. As for the nonscatterer density dependent generalized likelihood ratio test (NSDD-GLRT)

the influence of signal direction vector mismatched with steering vector on detection probability is analyzed theoretically. Moreover

the formulas for detection probability and false alarm probability are deduced

and the constant false alarm rate property of detector is proved. The experimental results show that NSDD-GLRT performs best when the target energy is uniformly distributed

and rejects the signal mismatched with steering vector effectively. In addition

the correlation between target amplitudes results in an additional loss for values of detection probability in the high range

and the fluctuation of target amplitudes also brings forth performance loss.