This is an old revision of the document!

Homestake meeting minutes, 01/08/15

Attending: Gary, Victor, Daniel, Gwynne, Vuk

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

1) Homestake status - duty cycle of existing stations? - any changes in timing? - antelope setup

Tanner (via email): The stations seem to be receiving the GPS time consistently (the last reset was 19 days ago) but we still have the timing issues. Hopefully we will fix that on our upcoming visit. I am working to get Antelope set up here at UMN so that we can stream the data here and build a database. I don't think I'll be able to finish by the end of the week but I can work on it remotely while in SD as long as I get Antelope actually installed.

I have built parts of 14 more cables for running from the digitizers to the GPS transceivers, but they are not totally complete. This is because we have several ideas for dealing with the GPS timing problems, some of which involve different adapters/converters. So there is no point in putting certain connectors on the cables until we understand the problem more fully. But I will be able to do that in Homestake once we get the problems figured out.

Vuk will be bringing an attenuator to place upstream of the first transceiver. If this does not solve the GPS locking problem, have additional connectors/attenuators to try at one of the stations - if it works, we can purchase and install more of them.

Gary still receiving the data online. Rock solid, surface machine pushing data to Indiana. Every few hours there is a glitch when the digitizer re-synchronizes. Can adjust it to send the data to UMN, and UMN can serve as distributor to others. Every times the digitizer synchronizes there is 0.25sec data gap and then a single sample spike. Will follow up with IRIS to understand better.

Daniel also working on the antelope, getting close to setting it up.

2) Planning next visit: Jan 12 - 23. Tanner and Daniel will stay the entire period, Vuk will join 01/11-16, Gary will join 01/18-23. To do list:

• Test the new equipment on the surface, huddle tests etc.
• Tests of the GPS system in Yates IT room, check amplitude and polarity of the 1pps signal.
• Send GPS signal from Yates IT room to Ross Hoist room.
• 300: power/network should be available, huts built. Install small battery, GPS transceiver, digitizer, seismometer. GPS/network through Ross. Probably use side access.
• 800: power/network should be available, huts built. Install small battery, GPS transceiver, digitizer, seismometer. GPS/network through Ross. Access via Yates.
• 4100-D: power/network should be available, huts built. Install small battery, GPS transceiver, digitizer, seismometer. GPS/network through Yates. Note: this is the station nearest to Yates.
• 4100-1: power/network should be available, hut built. Need to install optical fiber between this station and 4100-D for the GPS signal (and maybe network). This fiber was not purchased, but maybe we can use one of the fibers we purchased for 1700. Alternatively could get GPS via Ross. Install small battery, GPS transceiver, digitizer, seismometer. Note: this is the new station in Bill’s room.
• 4100-A: power/network should be available, huts built. Currently network via Ross, could get GPS via Ross too. Or, if we install the new fiber between 4100-D and 4100-1, we could get GPS/network via Yates. Install small battery, GPS transceiver, digitizer, seismometer. Note: this is the “best” station.
• 4850-2,3,4: move electronics outside of the enclosure.
• Troubleshoot the problem with radio’s, reconfigure the admin building antenna and the two field antennae (Yates and Ross).
• If weather allows, install other surface stations.
• Print and post DUGL labels.
• Enable access to the admin building radio antenna.
• Enable access to the master Q330.
• Connect the old surface machine to the internet, maybe use it as local data storage. Or else ship it back to UMN.
• Set up antelope: send data to UMN, then from there to Indiana and Caltech.

Vuk has found several vendors of batteries and smart chargers in Rapid City, plan to purchase them there (need a 12V, 12A, gel cell battery and a 12V, 1-1.5A charger at each underground station).

Daniel: huddle tests underground

3) Analysis of existing data

1. Estimation algorithms (Shivaraj, Eric, Noah)