Short-Time Fourier Transform (STFT)
Definition
A signal processing technique that applies a Fourier transform to successive short windows of a signal, producing a time-frequency representation. Used in ENF extraction to track how the dominant frequency near 50 Hz or 60 Hz changes over the course of a recording.
Related terms
- Cross-correlation
- A statistical measure of the similarity between two time series as a function of a time lag. In ENF matching, the extracted...
- Electric Network Frequency (ENF)
- The instantaneous frequency of the alternating-current mains supply, nominally 50 Hz in most of the world and 60 Hz in North America....
- ENF discontinuity
- A break in the continuity of the extracted ENF trace that is inconsistent with the reference database. Can indicate a deletion (missing...
- ENF reference database
- A continuously maintained archive of grid frequency measurements recorded at high temporal resolution, used as the ground truth against which a recording's...
- Transmission System Operator (TSO)
- The entity responsible for operating a high-voltage electricity transmission network in a given country or region. TSOs log grid frequency in real...
Explained in
- Electric Network Frequency Analysis for Audio DatingA signal processing technique that applies a Fourier transform to successive short windows of a signal, producing a time-frequency representation. Used in ENF...