Find a known pattern within a noisy signal
Radar Systems: Detect the return time of a transmitted pulse to measure distance.
GPS: Correlate satellite signals with known codes to determine position.
Template Matching: Find a known pattern (face, fingerprint, signature) in an image or signal.
Time Delay Estimation: Determine the lag between two recordings of the same event.
Formula: R_xh[k] = Σ x[n] · h[n-k] - slides the template across the signal