Looking at the data of last week-end (which are very clean in terms of glitches!), I noticed a persistent family of glitches around 30 Hz. In fact, this family has existed for a very long time. I can see examples in O2 data. The glitch rate is rather small, a few tens of glitches every day, and this is probably why this family has not been investigated (AFAIK). Now the data seems cleaner, this family is in the top of the list.
I had a first look at the glitches (see spectrogram in Fig. 1). This is what LIGO would call a rain drop glitch. I also scan *ALL* virgo channels to search for a coincident glitch: there is none.
I guess this post is a call for volunteers to investigate further this glitch family. I'm posting a list of GPS times of the glitches of last week end. Some of them are so loud they produce an range drop or even a lock loss.
GPS - Frequency [Hz] - SNR
1234311598.3945 31.40 29.14
1234311603.6055 31.40 23.39
1234312342.7695 31.40 52.49
1234312914.2617 31.40 27.40
1234312969.8164 31.40 50.15
1234313468.9648 31.40 73.74
1234314328.2070 31.40 825.42
1234315169.9258 31.40 103.66
1234316898.2930 31.40 13.96
1234322170.1289 31.40 302.52
1234325354.9727 31.40 30.66
1234325356.2070 31.40 11.42
1234325375.5039 31.40 31.51
1234325673.2461 31.40 32.98
1234325935.9492 31.40 15.55
1234326187.6289 31.40 683.17
1234326209.5352 31.40 1232.40
1234326274.2383 31.40 60.53
1234326331.3477 31.40 259.32
1234326367.7148 31.40 11.12
1234326393.8867 31.40 11.43
1234326438.6133 31.40 45.99
1234326451.5586 31.40 56.98
1234326482.2539 31.40 40.20
1234326545.2773 31.40 51.39
1234326554.3242 31.40 32.78
1234326740.0586 31.40 46.47
1234326746.2617 31.40 13.69
1234326819.0430 31.40 381.75
1234326834.5273 31.40 10.92
1234326955.3164 31.40 160.32
1234329917.3945 31.40 28.33
1234331193.4805 31.40 18.52
1234339428.3867 31.40 271.20
1234385870.7852 31.40 13.71
1234391955.5586 31.40 756.79
1234392857.0586 31.40 82.00
1234397370.0117 31.40 10.19
1234400044.5742 31.40 74.66
1234432599.9258 31.40 412.29
1234455907.7930 31.40 14.96
1234457434.4258 31.40 336978.43 (lock loss!)
1234462773.6914 31.40 16.72
1234474319.1055 31.40 473.80
1234477166.6055 31.40 29.01
1234477837.8398 31.40 10.98
1234482283.3789 31.40 24.66