Skip to content

Electric Network Frequency (ENF)

Definition

The instantaneous frequency of the alternating-current mains supply, nominally 50 Hz in most of the world and 60 Hz in North America. It fluctuates continuously around the nominal value in a pattern driven by supply-demand imbalances on the grid.

Related terms

Camera flicker / optical ENF
The periodic brightness variation captured in video recorded under mains-powered fluorescent or LED lighting. The lighting modulates at 100 Hz or 120...
Cross-correlation
A mathematical sliding-window comparison that measures the similarity between two time series at every possible time offset. In ENF analysis it finds...
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...
ENF splice detection
Using breaks or discontinuities in the ENF time series to identify edits, cuts, or inserted segments in a recording. A genuine unedited...
Geographic grid disambiguation
The process of determining which national or regional grid a recording's ENF trace came from, since the 50 Hz grids of continental...

Explained in

Your journey to becoming a forensic professional starts here.

Practice with mock tests, learn from structured notes, and get your questions answered by a global forensic community, all in one place.