News ...

ENF of Mainland Greece in Real-Time

At DSIP Lab (Digital Signal Processing Laboratory, ECE, University of Patras) we are recording the Electrical Network Frequency (ENF) of Mainland Greece since July 2016. We make all data available for free.

As of April 2023 a new system has been added that makes the ENF measures available in Real-Time, along with the Min, Max, Avarage and Variance of the last 12000 measures. See

The Electrical Network Frequency (ENF) Criterion is a forensic technique used to identify the authenticity of a digital recording. Since the power line signal interferes with all kinds of recordings (telephone, video, biosignals, …), the availability of the ENF signal data for Greece could facilitate the authenticity of a recording, and the time and place that this recording has taken place. This is made possible by comparing the frequency pattern between the background utility hum in the evidence and long-term records of the ENF.

To obtain such a long term record of the ENF fluctuations at national level, we have ported the power line frequency recording system to a Raspberry Pi 3 Model B. This has rendered the whole system small in size, portable, and of low cost. The system captures the power line signal and extracts the ENF signal for mainland Greece, 24/7. The ENF data are uploaded to the cloud for free download by all those who are using the ENF in their research. More info can be found at the followig links:



Data and code are made available for free download. (

<< Go back to the previous page