Calibration Strategy and Efficiency measurement of the Muon Identification procedure at LHCb

We present a strategy for calibrating with data the LHCb muon identification procedure and for extracting in-situ the performance. Two main calibration samples are used: the inclusive $J\psi \to \mu\mu$ decay as a source of muons and the $\lambda(1115.7)\to p\pi$ decay as a source of hadrons decaying and non-decaying in flight. For each of them we describe the selection, the expected purity and the rates for different running scenarios. The distributions extracted from calibration samples are compared with those obtained from a generic b-inclusive sample. An estimate of the precision that can be reached in the evaluation of the muon identification efficiency and misidentification rate is given as a function of the collected statistics.