REDUCE_SWITCH - reduce the switch sequence for a SCUBA observation

Description:

This application takes a SCUBA demodulated data file and splits the data array up into its various `planes'; data, variance and quality. In addition, the application reduces the component switches of an exposure to give the exposure result. Optionally, the routine will divide the internal calibrator signal into the data before doing either of these things. It is also possible to select a single switch from the input data.

For skydip data, this routine calculates the sky temperature for each integration and sub-instrument.

Usage:

reduce_switch in out

Parameters:

IN = NDF (Read)

The name of the demodulated data file. If SCUBA_PREFIX is set this can be the number of the observation rather than the full filename.

MSG_FILTER = CHAR (Read)

Message filter level. Allowed values are QUIET, NORM and VERB. Default is NORM. There are no verbose messages.

OUT = NDF (Read)

The name of the file to contain the output data.

SPIKE_LEVEL = INTEGER (Read)

Number of spikes tolerated before marking data point bad. The default is that the sample should be marked bad if the transputers detected more than 5 spikes during a 1 second sample.

SWITCH = INTEGER (Read)

Parameter to indicate which switch to extract. A value of 0 means that all switches should be reduced. Default is 0.

TARRAY = LOGICAL (Read)

Controls whether the T_COLD parameters are read as an array of values (true) or read as a sequence of scalars (false) . This parameter is useful if the command is to be run in batch mode. Default is false.

T_COLD = REAL (Read)

Temperature of the cold load when processing skydip data. The default value is taken from the input file.

T_HOT = REAL (Read)

Temperature of the hot load when processing skydip data. The default value is taken from the input file.

USE_CALIBRATOR = LOGICAL (Read)

Yes, if you want the data for each bolometer measurement divided by the corresponding internal calibrator signal. The default is not to use the calibrator.

Examples:

reduce_switch

All parameters will be requested.

reduce_switch test nosw

This will reduce the switch from input file test.sdf without dividing by the calibrator signal and tolerating up to 5 spikes in a 1 second sample. The output data will be written to nosw.sdf.

reduce_switch test nosw SWITCH=2

This will select switch 2 from test.sdf and write it to nosw.sdf

Notes:

If the input file is not found in the current directory, the directory specified by the DATADIR environment variable is searched. This means that the raw data does not have to be in the working directory. In addition IN accepts a number. This number is converted to a demodulated data filename by prepending it with information specified in the SCUBA_PREFIX environment variable. This filename expansion only works for demodulated data (ie data containing '_dem_'). The '_dem_' is assumed and should not be present in SCUBA_PREFIX.