This statement in the Virgo Website is false:
"First detection of gravitational waves -
On the 14th of September 2015, a gravitational wave was detected for the first ever time. "
I say this because my father was a fringe scientist obsessed with gravity waves, and invented a device nearly two decades ago which could detect gravitational waves via the ELF/ULF frequency range. Although my father has been deceased for nearly ten years, the schematics to his ULF receiver can still be found at http://elfradgroup.com/ in the Antenna & Receiver section. The website is outdated due to it being untouched since his passing, however the information is available to any and all who wish to utilize it.
Happy hunting!
- Museteri
(aka: Terina Plyler)
To my knowledge, there is no (peer-reviewed) proof that your father found any gravitational wave. Moreover, from the information on the website you provided, there is no sign these antennas can detect gravitational waves.
Therefore, I am afraid that the sentence on the Virgo website is correct, unless until you show the proof your father observed some gravitational waves (and additionally convince the astrophysics community that the proof is solid).