Single-pass flaw detector for magnetic media

A simple flaw detector that enables reliable single-pass defect location in magnetic media is described and analyzed. The envelope of the playback signal is detected in a phase-independent manner, small variations in envelope indicate the presence of a defect. The detector may be configured as a biased or unbiased estimator of the envelope of the input signal. Synchronous, asynchronous, analog, digital, biased, and unbiased forms are discussed.<
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