Homestake Meeting Minutes, 04/30/15

Attending: Tanner, Daniel, Gary, Pat, Victor, Noah, Vuk

Homestake wiki: https://zzz.physics.umn.edu/groups/homestake/home

Our agenda:

• Homestake status:
  • 1700: missing the GPS link. Probably GPS unit in Q330 not working, try to replace it.
  • 2000A: missing entirely, can't talk to it. Tanner talked to Jamey, can talk to the switch at this station, so the power should be on. Have to visit it and troubleshoot.
  • 2000E: unlock seismometer? replace hardware? Gary: there is a screw on each of the STS-2 feet that may need to be adjusted. But likely the issue is more than just these feet, could be a site inducing tilt events. Look for water and other obvious problems. If we see nothing, we should replace the sensor.
  • Yates: power box replacement? Gary: PASSCAL is sending the power box and replacement cables. The problem should be one of these. We will also have several batteries, will need to replace the one at Yates. Daniel and Tanner can check it out when they arrive on Thu May 14, and replace the battery. COuld try to read the power coming off of the solar panel.
  • data quality shifts going on. Vuk: could use the power fluctuations in surface stations as a diagnostic… If it stops, it's a sign of trouble.
  • data flow: Daniel and Tanner: seems stable. Daily email notifications still state only 11 stations. Tanner: Gary probably needs to update the metadata to fix this…
  • other? Tanner: had a power outage a few weeks ago, talked to admins but no clear reason. Also, they will be moving the servers in mid-late May, so there will be an outage then as well. Can always go back to get the data, rsync-ing or scp-ing. Caltech and IU would also have to do it, scp-ing from Homestake works fine. Vuk will talk with UMN admins to figure out how to minimize the down-time due to the move.

• Next Homestake trip, May 14-23
  • planning for active excitations: Victor and Gary to take the lead. Victor: will need permissions for the weight drop experiments. (200 lb is the smaller and the larger is about 600 lb) Tentatively, planning to do this in July or August.
  • Daniel and Tanner arrive on 14th, visit to the hardware store and do huddle test, and visit Yates station.
  • Pat should check with Gary regarding the return date.
  • High-school site, network, computing: Gary: need to get in touch with the IT people to start working on the network. There may be a connection with one class. Could use the existing computer in the Yates admin.
  • Rhyolite Ridge: Vuk to make contact.
  • far stations: Gary: we are set with the older lady, all set there. The older man in Strawberry Hill is away, can't do it there - can't do it this trip, may have to do it later. We'll have to scout for the third site.
  • underground trip, one day should suffice? Should be ok, but we need to bring enough of spare equipment. At 2000E, if the problem is with the tile we may need to come back the following day. Should schedule another 1/2 day as a backup.
  • do we need anything else from PASSCAL? Gary will check with PASSCAL about replacement for a Guralp. Will need also another STS-2. Vuk to contact PASSCAL about this.

• data analysis
  • calibration: Daniel has scripts to apply the generic response to the data. But we may be able to have specific calibrations to individual instruments - should ask PASSCAL or Gary about this. Daniel will take the lead on this.
  • radiometer method: Noah: running more tests including noise along with the signal and recover it. So far, successful recoveries with all 3 wave types. Tanner: also looking at the code and re-organizing it, working with Noah to understand the code. Hope to look at the real data in a couple of weeks.
  • data analysis workshop: Victor: good idea, would be good to sit together and decide what kind of analysis we want to do. Victor has a trip in late August/early Sept. Tanner prefers fall, August looks full with the LIGO meeting in late August. Pat will be gone until Sep 1. Daniel: no constraints. So, September might be best.