On-site personnel: The AGO team consisted of Beth Bergeron and Jason Anthony (Field personnel/Groomer) and Joe Kujawski (AGO technical service team).

Station: The station was cold upon arrival. The Primary failure mode was a short between the TEM and chassis. This caused two separate secondary failures: 1) The PSC failed. The PSC is intolerant to power supplies with less than 1 MOhm isolation between the power and chassis. 2) The turbo failed (for lack of power). This caused the exhaust to ice. Also, there was significant ice formation in the TEG manifold and exhaust system. The technical service team successfully started the thermo-electric generator and raised the station temperature to 20-25øC. That temperature was maintained throughout the service call. AGO-1 was not targeted to be raised this year and will not need to be raised for several years.

TEG: The TEG Turbo was modified to enable it to extract power directly from the PSC. This will allow it to become the highest priority power user at the AGO station. New batteries for the turbo were installed. Batteries for the electronic shutoff valve were changed. Manifold propane pressure was set to 4.3 psi. The maximum burner temperatures that could be achieved are: #1: 275 deg C, #2: 270 deg C, #3: 270 deg C, #4: 285 deg C, #5: 250 deg C, #6: 250 deg C with a freon pressure of 16psi. Maximum burner temperatures range up to 300øC with a freon pressure of 24psi. The fin plates were installed to restrict air movement from the TEG fins by 75%.

Data Control Unit (DCU): Two Storage computers (Rev 2, SN: 00-001 and 00-002) were installed in the DCU. The old storage computer disks were removed and will be shipped to Augsburg College for data retrieval and processing.

Power Supply Controller (PSC): The PSC had failed due to a short in the TEG. This caused a failure in the battery charger system power delivery system on CAGOEXP (Q68 failed). The board was replaced and the PSC was made to work. Another short in the newly rebuilt TEG caused a failure in the new BAGOEXP. This board was also destroyed. A temporary fix on the board allowed the service team to continue testing the station. A new PSC was brought in on the pull-out flight and installed while the plane was on the ground.
  See AGO1.AGO for experiment power settings, priorities, and other station  information.

Data Acquisition Unit (DAU): All functions were normal when the unit was turned on. Non-volatile random access memory was tested and determined to be good. The DAU software was upgraded to Rev. 3. See AGO1.AGO for DAU settings.

Global Positioning System Receiver (GPS): The GPS was functional when the AGO electronics were turned on.

Bell Labs Fluxgate Magnetometer: Data was examined to verify the operation and leveling of the magnetometer. By examining this data, the service team determined that there was no need to  change the magnetometer settings. Settings for the magnetometer are: Sensitivity : 1000 nT

The electronics were checked out per the servicing documentation. The results of the checkout were as follows:
 

Tohuku ULF Search Coil: Sample data were recorded to disk. These data were examined to determine functionality of the instrument. Sample data were collected and stored to the laptop.

Stanford VLF Receiver: Stanford's upgrades to the BB-snapshot system and battery elimination system were installed and tested. These upgrades functioned as expected and did not interfere with other experiments. The Stanford experiment was not calibrated since calibration instructions using the function generators did not exist. Data were collected and examined for possible problems.

Settings for the experiment are as follows:
8-16 KHz     20
16-32 KHz   20
0.5 - 1KHz  20
4-8 KHz      20
24.0 KHz NAA     RF-20     IF-15
1-2 KHz NS 10
2-4 KHz       10
30-40 KHz  10
1-2 KHz EW 10
Line Receiver NS 30
Line Receiver EW 30
Sample data were collected and stored to the laptop.

University of Maryland Riometer: The signal attenuators provided by the University of Maryland were installed. After installation, data was observed and found to be noisy in both channels. This noise is similar to noise seen last year which was determined to be normal instrument operation at this time of year. See P100_RI1.GIFand P100_RI2.GIF for collected data. Sample data werecollected and stored to the laptop.

Anubis Seismic: The service team was sent into the field without the equipment or software needed to initialize the DAS. An attempt was made to install and initialize the equipment while the LC-130 was on the ground. This attempt was unsuccessful.

Dartmouth LF/HF Receiver: Dartmouth was upgraded for the higher data sample rate. Data were collected and examined on the Dartmouth experiment. Sample data can be seen in P100_AOF.GIF. These data were taken when the Allsky camera was not powered. (See also the interference test section). Sample data were collected and stored to the laptop.

Allsky camera: The Allsky camera upgrade was attempted. After the power board was upgraded, there was a short between the primary and secondary grounds. This board was removed and replaced with the spare power board. The Camera Control board upgrade was also attempted. This upgrade also failed and had to be replaced with the spare camera control board. During testing of the camera, it was discovered that noise from the camera was very high during the integration cycles. (See interference tests). Since the camera noise is only for the short integration time (6 seconds out of every minute during the night), the decision was made to keep the camera in the station with the upgrade in place. Confirmation of this decision was requested of Rosenburg or Stanford and Dartmouth. Sample data were collected and stored to the laptop.

NASA LIDAR: NASA LIDAR was removed from AGO-1. Note that there was about 1/2" thick ice on each of the three windows in the LIDAR top-hat.

Interference testing: Interference testing was done by turning on each experiment and observing the data from the Dartmouth experiment. Note that the baseline data indicates that there is some low frequency noise present during testing which was not present at other times during the visit. A Station source for this noise could not be identified.

Time                       Image            Description
2000:327/00:00:00 INTR00.GIF All experiments, no seismic
2000:327/00:10:00 INTR01.GIF Only Dartmouth + station
2000:327/00:16:28 INTR02.GIF Only Dartmouth & station (no TEG)
2000:327/00:22:46 INTR03.GIF Station on, Dartmouth, Allsky (no image)
2000:327/00:29:10 INTR04.GIF Station on, Dartmouth, Allsky (image capture)
2000:327/00:34:34 INTR05.GIF Station on, Dartmouth, Stanford
2000:327/00:41:32 INTR06.GIF Station on, Dartmouth, Search Coil
2000:327/00:49:09 INTR07.GIF Station on, Dartmouth, Riometer
2000:327/00:54:44 INTR08.GIF Station on, Dartmouth, Fluxgate
2000:327/00:59:40 INTR09.GIF Station on, Dartmouth, Seismic

Also, at 2000:327/01:05:00, the Stanford, Allsky, and LF/HF experiments were all on. Stanford BB snapshot was active taking data. At 2000:327/01:30:00, the BB snapshot took data at the same time as the Allsky was capturing an image. See P1_ch16I.dat for raw Stanford data covering this time period.

Miscellaneous: GPS position: S 83  52' E 129  37'. Elevation: 2813 m.

Notes for the future: 1) The field service team should bring a complete rack level spare PSC instead of spare boards. 2) Whenever a power source or experiment has been modified, it should be tested for greater than 1 MOhm isolation to chassis BEFORE the unit is connected to the PSC. Note that the PSC is very sensitive to violations of this specification.