Mopra Schedule File Creator: Position Switching V4.5

Observer initials:
MOPS Configuration:
Central Frequency:  MHz
MOPS Zoom Band 1:   Enter up to four numbers, separated by a comma. (e.g. -37,-43,-51)
MOPS Zoom Band 2:
MOPS Zoom Band 3:
MOPS Zoom Band 4:
Doppler Tracking: enabled    disabled
Radial Velocity: km/s *     Frame: LSR    Barycentric
Integration time per ON Position: s
Spectral averaging interval: s *
ON-OFF Pattern: symmetric (OFF-ON-ON-OFF)    non-symmetric (OFF-ON-OFF-ON)
Tsys (paddle) measurements every: min *
Duration of Schedule: min
Coordinate system:   B1950  J2000     Galactic
Source Name:
Source Position: RA/GLONG:    DEC/GLAT: 
Offset of the ON relative to source: RA/GLONG:    DEC/GLAT: 
Reference (OFF) position: relative to ON      absolute position

To refresh the screen using the default entries, press SHIFT and click the 'reload' button simultaneously.

Note that this schedule file creator assumes a cycle time of 2s.

This output should be saved on your local computer (.sch) and then uploaded to the Mopra control computer bigrock.


The project number assigned to your proposal.

Example: M007

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Observer Initials

Initials or short name of the observer(s).

Example: ZOZ

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MOPS configuration

Select a MOPS configuration from the menu. MOPS refers to the Mopra Spectrometer, the new polyphase digital filterbank. MOPS is now the standard mode. MOPS can operate in wideband mode (8.2 GHz bandwidth) or zoom mode (137.5 MHz bandwidth). There is an option for the wideband mode to observe with only 1024 channels and therefore reduce the size of the data files. This third option is rarely used.

Example: MOPS Zoom

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Central Frequency

The centre frequency of the 8 GHz covered by MOPS. If Doppler tracking is enabled, the frequency here will be interpreted as the rest frequency of the observed line. If Doppler tracking is disabled the frequency here would be the actual observing frequency (sky frequency).

Make sure your frequency is within these limits:

Example: 92900

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MOPS Zoom Band values

For MOPS zoom mode use the script available on pyroclast to determine which values to enter into the 4 spectral windows of each band. For unused windows leave blank.



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Doppler Tracking

Enable/disable Doppler tracking. Note that this only adjusts the centre frequency, it does NOT continuously track the Doppler shift during an observation. For observing with MOPS it is recommended that Doppler tracking be disabled.

Example: disabled

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Radial Velocity

The radial velocity of your source. Also choose the reference frame, LSR (local standard of rest) or barycentric. The radial velocity information provided here will be ignored if Doppler tracking is disabled.

* Note: If Doppler tracking is disabled (recommended for MOPS) and no radio velocity is specified (also recommended) then you must adjust your sky frequency to account for the velocity of both the source (LSR or barycentric) and the velocity of the observatory relative to the rest frame. An online tool is available Frequency Calculator to calculate this adjustment.

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Integration time per ON position

Integration time on your source in seconds for each individual sub-scan. The corresponding reference (OFF) sub-scan will be observed with the same integration time. Don't make this value too large (say larger than a couple of minutes) as the sky conditions may change while you are on source.

Example: 60

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Spectral averaging interval


Number of seconds to average spectra over before writing to disk. Default is no averaging (2s). However, for high data rates averaging is recommended.

Example: 2

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ON-OFF Pattern

Two different patterns to are provided: The symmetric pattern will perform observations as OFF-ON-ON-OFF while the non-symmetric pattern will alternate between the the ON and the OFF position like OFF-ON-OFF-ON... The symmetric pattern has the advantage of reducing driving times, whereas the OFF integration of the non-symmetric pattern can be chosen to be toward the same patch of sky as the ON position. For the latter you may provide the reference position relative to the ON (see below) by selecting an RA offset of the reference position equal to the negative of the integration time.

Example: symmetric

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Tsys (paddle) measurements

For observations in the 3-mm band only. Approximate time between Tsys measurements, i.e. ambient load calibration using the paddle. The true intervals between the Tsys measurements may vary slightly from the input due to other constraints of the schedule. The value provided here acts as an upper limit.

* Observations in the 12- and 7-mm bands do not require a Tsys (paddle) measurement. To avoid entering a Tsys measurement in the schedule file you must enter a time much larger than the duration of the schedule (e.g. 999). Then delete the following lines from the schedule file text output:
$unit 2

Example: 30

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Duration of Schedule

Total duration of the observing pattern in minutes. This 'total time' includes all ON and OFF integrations but not driving times and time needed to perform Tsys measurements. It is recommended that the maximal time is not longer than 60 min in order to perform pointing scans between.

Example: 15

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Coordinate system

The coordinate system of your coordinates. You may choose between equatorial (J2000 or B1950) or Galactic coordinates. Please take care of the format: Equatorial, RA: hh:mm:ss DEC: dd:mm:ss, Galactic GLON: ddd.xxxxx GLAT: dd.xxxxx. It is your responsibility to input the coordinates in the right format.

Example: J2000

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Source Name

Specify the name of your source here. If you leave the source name unset, you will create a generic schedule file and can pick your source from a catalogue file that you create.

Example: Orion

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Source Position

Please provide the source coordinates in the specified coordinate system here. All relative offsets (ON and OFF) are computed relative to the coordinates specified here. If you leave the source position unset, you will create a generic schedule file and can pick your source from a catalogue. However, you must provide the source position if you are using an absolute position for the reference.

Example: RA: 23:41:32  DEC: -82:43:09

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Offset of the ON relative to source

The location of the ON position relative to the source coordinates. Generally not used.

Example: RA: 00:02:00  DEC: -00:10:00
will shift the target position 2 time minutes to the east and 10 arcseconds to the south.

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Reference (OFF) position

The position of the reference (OFF) integration. You may choose between relative and absolute positioning. The relative position refers to the position you provided for the the source coordinates. Alternatively, you may provide an absolute position for the OFF integration. Depending on the coordinate system you choose, the coordinates must be given in sexagesimal or decimal format.

Example:  absolute   RA:  12:33:15.3   DEC:  -72:54:04.8

Example:  relative   RA:  00:00:00.0   DEC:  -00:15:00 (offset of -15 arcmin in dec)

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Original: Juergen Ott (11-July-2005)
Modified: Kate Brooks (10-March-2009)