Archiving Mees Solar Observatory Data

Mees to Manoa

Data from most of the Mees Solar Observatory instruments is recorded on exabytes (or videotape) in real time. The tapes from the different instruments are then held until a significant quantity has accumulated. When this occurs, Garry Nitta at Mees culls the tapes into a shipment, which usually consists of 50 tapes. The tapes are then sent via the US Postal Service to the IfA at Manoa. There is generally one shipment of tapes every two to three weeks, depending on observing conditions, special campaigns, etc.

Before sending the tapes, Garry makes a list of each tape that is included in the shipment. He then emails this list to the responsible person in Manoa, informing them that a box of data tapes is on the way.

Upon receiving the box of tapes in Manoa (generally one to two days later), the responsible entity should open the box and check its contents against the list sent by Garry. They should send a message back to Garry confirming that each of the tapes on the list was received. A copy of this message, listing each tape and acknowledging receipt should be saved.

Data Types

There are several different types of data that come from Mees, and all get handled a bit differently one they get to Manoa. Currently, we receive the following data from Mees:
There are separate Data Camera and Frame Grabber exabyte tapes, usually one to two tapes of each type (usually, but not necessarily the same number of each type) per day. These tapes are filed in the data library in C-216.
There is a file that lists all of the MCCD tapes in the archive. I have kept this mostly up-to-date out of some odd sense of duty, but whether there is any need for this file is not clear.
These are acknowledged to Garry as being received and the tapes passed on to Kristin Blais, who takes care of filing them. There is generally one tape per observing day.
These are handled the same way as the K-Line tapes. Up to now, there have been fewer POI tapes than K-Line tapes.
The IVM generates several different types of data tapes. The most common is the tarlog tape. These tapes hold the tar files for two to three days of patrol magnetograms. These tapes should be filed according to the date of the first tar archive on the tape. The second type of data tape is the flare mode tape which holds the magnetograms that were written directly to tape during high time cadence observations. There is generally only one of these per day when the flare mode is being used. These are filed according to the date on the tape. There are also other tapes containing special observations which should be filed according to date as well. In addition, with any IVM tarlog tapes, there are printouts of the tar -t output included. There hardcopies of the tape directories should be filed chronologically in the IVM Tarlogs Logs binder in the data library (C-216).
H-alpha Coronagraph
This data is recorded on videotape in Super-VHS mode. Each video tape, recorded in slow play mode (2 hours/tape) generally covers 2 weeks of observations. After acknowledging receipt, these videotapes are put in on the bookshelf in the printer room (B-115).
The Mees White Light Telescope generally generates one tape per 1-2 weeks. These arrival of these tapes is acknowledged and they are filed in their drawer in the data library (C-216).
Haleakala Stokes Polarimeter
The Stokes Polarimeter data is handled differently than the other data from Mees and these specific data handling procedures are described in its own page.

The Data Library

The data library is locvated in the C-building, near the auditorium, in C-216, and has been dubbed Digital Mongolia by Sandy McClymont. The data library essentially consists of eight old punch card filing cabinets, which work very well to hold exabyte tapes. The capacity of a single cabinet is approximately 1000 exabytes, with 108 exabytes per drawer. As of November, 1995, the MCCD occupied two and one-half cabinets, the K-line, one and one-half, the IVM one-half, the Stokes Polarimeter one drawer, and the MWLT one drawer. The individual drawers are labelled with the data type and time interval included in the given drawer.

There is currently a system of index cards used for "checking out" exabyte tapes. The index card is filled out with the initials of the checker, the data type and date of the checkee, and the date it was checked out. The card is then put into the drawer in place of the exabyte that is being taken out.

The drawers of the filing drawers are quite uneven and make it difficult to move the tapes around. In order to make a smooth bottom for the drawers, I have cut up the boxes that the exabytes tapes come in (the 10-tape boxes only). Using two of these, appropriately trimmed and pressed together with the sliding partition in each drawer, leaves a smooth bottom for the drawer.

When too many larger boxes (in which the individual tape shipments come) accumulate, I take them over to the Manoa Post Office to the table they have for discarded boxes for someone else to use.

The page written by Kevin Reardon on 14 November, 1995
The current Mees Data Archivist is Litao Jiao.
This page last updated 17 November, 1995.