## Global SIC default variables

By default, i.e. without reading any data, MIRA defines the following SIC variables:

    doPause                      ! Logical GLOBAL

which can be set to `.true.` or `.false.` with

    let doPause yes

respectively

    let doPause no

It is used to halt the execution of `MIRA\SOLVE` until the user types `continue`.

    writeXML                     ! Logical GLOBAL

is used to write (`let writeXML yes`) XML files with pointing, focus, and calibration solutions applied to the data (respectively to suppress this via `let writeXML no`). The files are named `iram30-pointing-20071022s99.xml` for pointings, and `iram30m-focus-...` and `iram30m-calibration-...` for focus solutions and calibration parameters, respectively.

The following variables are used by the automatic online data processing (see section 2), and specify, for the 30m file system, the paths to the imbFits raw data location (ncsData) and to the MIRA data products (visData), respectively:

    ncsData                      ! Character*  256 GLOBAL
    visData                      ! Character*  256 GLOBAL

Global SIC variables for calibration purposes:

    calByChannel                 ! Logical GLOBAL

By default, one separate calibration temperature is applied for each spectral baseband. If you want to use a different calibration temperature for each spectral channel, use `let calByChannel yes`) before reading a calibration scan. This feature is to be used e.g. if the image gain is not neglectable (e.g. DSB tuning) and varies significantly across the spectral bandpass.

    calCheck                     ! Logical GLOBAL

The SIC logical variable `calCheck` (default: `.true.`) allows to check the consistency of an observation and its calibration measurement. If only part of the backend units are calibrated, then MIRA tries to identify backend units that can be calibrated. Use `let calCheck = no` when you connect two or more parts of the same backend to the same receiver, with identical spectral setup (otherwise the assignment of the calibration parameters will not be unique anymore).

    ignoreTraceflag              ! Logical GLOBAL

The `TRACEFLAG` parameter in the raw data indicates whether the antenna was in a defined state (e.g. tracking or scanning) or not. The latter may happen in the data if synthesizer data are taken while the antenna is in stow position (thus simulating astronomical observations). The default is `let ignoreTraceflag no`. For data taken while the antenna is in stow position please set it to `yes`.

    badLevel                     ! Real GLOBAL

The `badLevel` parameter allows to automatically flag bad spectral channels. Default: if in the calibration the total power of a spectral channel is more than a factor 20 above or below the median total power across the baseband under consideration, this raw data point will be flagged (and the calibrated spectral channel too).

    flagBSwSpikes                ! Logical GLOBAL

A recent analysis has shown that some dumps in beam switched pointings have abnormally short integration times (5 msec and more below the nomincal value). However, the actual integration times are longer. The wrong normalization (from counts to count rates) thus results in spikes. With `let flagBSwSpikes .true.` this data are automatically flagged (default: no flagging).

    timingCheck                  ! Logical GLOBAL

By default (`timingCheck = yes`) MIRA checks that each backend data point is framed in time by data point from the other data streams (subreflector, antenna, fast and slow traces). If this is not the case although the data point is between the nominal subscan start and end time, the latter are modified accordingly in order to avoid hazardous extrapolations. This automatic correction can be switched off by setting `let timingCheck no` (after a change of the `timingCheck` flag, the scan needs to be read again in order to validate the new settings.

    traceExtrapolation           ! Logical GLOBAL

Only for `timingCheck = no`. Allows for extrapolation of antenna trace data (fast and slow) for backend data at scan start without a trace data point before, or for backend data at scan end without a trace data point after.