The effectiveness of Time-Reversal (TR) focusing has been demonstrated in various fields of ocean acoustics. In TR focusing, a probe source is required for a coherent acoustic focus at the original probe source location. Recently, the need of a probe source has been partially relaxed by introduction of the concept of a Virtual Source Array (VSA) [S. C. Walker, Philippe Roux, and W. A. Kuperman, J. Acoust. Soc. Am. 125 (6), 3828-3834 (2009)]. In this paper, Adaptive Time-Reversal Mirror (ATRM) based on multiple constraint method [J. S. Kim, H. C. Song, and W. A. Kuperman, J. Acoust. Soc. Am. 109 (5), 1817-1825 (2001)] and Singular Value Decompositon (SVD) method are applied to a VSA for robust focusing. The numerical simulation results are present and discussed.