  In this work, we exploit the sector level sweep of the IEEE 802.11ad
communication standard to implement an opportunistic radar at mmWaves and
derive an adaptive procedure for detecting multiple targets (echoes) and
estimating their parameters. The proposed detector/estimator extracts the
prospective echoes one-by-one from the received signal, after removing the
interference caused by the previously detected (stronger) targets. Examples are
provided to assess the system performance, also in comparison with the
canonical matched-filter peak-detector and the Cram\'er-Rao bounds. Results
indicate that the proposed method is robust against the signal spillover and
the near-far problem caused by the imperfect auto-correlation of the probing
signal and, for the same probability of false alarm, grants detection and
localization performances close to those previously obtained in a simplified
single-target scenario.
