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Problem

Take a textual receiver calibration file and enter it into the MySQL receivers database.

Solution

Calibration file format

A calibration file consists a header followed by one or more channel descriptions. Each line of the header consists of a keyword followed by its value, e.g.,

Technician:     J. Bauserman

The header values are receiver, engineer, technician (optional), date and bandwidth in MHz, e.g.,

Receiver:       RcvrPF_1
Engineer:       G. Anderson
Technician:     J. Bauserman
Measurement Date:  July, 2003
Measurement Bandwidth:  20 MHz

The channel values are receptor name, beam index, polarization and zero or more notes (optional), e.g.,

Channel: XLC_450
Beam: 1
Polarization: X Linear
Notes:   T-cold: 80.7 K   T-hot: 295.8 K (in X-pol) 295.8K (in y-pol)
Notes:

The keyword/value pairs must be placed one per line and their form exact. Spacing in a line is irrelevant. Most channel keyword's values are specific to a receiver, any illegal values are identified during database entry.

A row of the data table consists of frequency in GHz, receiver temperature, low cal and high cal (optional) respectively. The actual values must exist in contiguous rows and are immediately preceded by a line whose first non-white character is 'F'. The end of the table is signaled by an empty line. Examples are:

F   Trx   LowCal
11.8   28.35   2.55
12   19.31   2.16
12.2   16.29   2.08
...

F       Trx     LowCal  HighCal
1.1   34.98   2.93   22.63
1.104   28.96   6.06   20.26
1.108   17.59   0.54   20.4
...

Freq     Trx   LowCal
17.9   49.69   6.96
18   34.03   6.72
18.1   33.11   7.2
...

Fsky(Ghz)   Trx      Low Cal   High Cal 
3.900       17.05     3.48      33.03
3.940       11.01     3.56      36.27
3.980       21.20     3.87      40.80
...

Reading, checking and entering the data into MySQL

1. Log into a linux machine
   • $ source /home/gbt/gbt.bash # for bash users
   • $ source /home/gbt/gbt.csh # for csh users
2. cd to the directory that contains the calibration file or precede '_calibration_file_' with the file path.
3. Enter the command: updateRcvrTcals (path/)_calibration_file_

If the program has problems parsing the calibration file, it will generate errors preceded by the line number, otherwise it will display graphs of the calibration values and print keyword values as they were parsed. If you neglected to run the command from the directory containing the calibration file or didn't precede the calibration file name with the path to the directory you won't get any error messages and no graphs will be displayed. To then save the calibrations to the database and thereby make them available as part of their observational data, select Save either from the File menu or the Save icon (a floppy disk) on the tool bar and enter the password. Good citizens will then verify that their calibrations are available in the database.

Verification

Use ReceiverCalibrationsViewing to interrogate the database for your data.

Note: Raw text receiver calibration files for electronics are kept in /home/doc/gbt/subsys/rxcommon/tcal.

-- MarkClark - 15 Nov 2006