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Parkes Schedule File Creator: Position Switching

Observer initials:
Frequencies: IF1:  MHz    IF2: MHz
Correlator Configuration:
Correlator Cycle Time:
Doppler Tracking: enabled    disabled
Velocity Frame: LSR-KINEMATIC    LSR-DYNAMIC   Barycentric   Topocentric
Integration time per ON Position: s
ON-OFF Pattern: symmetric (OFF-ON-ON-OFF)    non-symmetric (OFF-ON-OFF-ON) disabled (SB option)
Duration for each source: min
Coordinate system: B1950 J2000 Galactic
Offset of the ON relative to source: RA/GLONG:    DEC/GLAT: 
Reference (OFF) position: relative to ON      absolute position
Source List:
Advanced options:
Enable DFB Tsys logging (select "No" for MBCOR)? Yes     No
Standing wave mitigation? Yes     No
New file for every source? Yes     No

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

This output should be saved on your local computer (.sch) and then uploaded to the Parkes system upon your arrival.


The Parkes project number assigned to your proposal.


Initials or short name of the observer(s).

Receiver and Central Frequencies

The reciever and centre frequency(s) of your observations. 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(s) is within these limits (in MHz):

H-OH 1090 2000
MULTI 1250 1550
GALILEO 2000 3000
1050CM 2600 3600
METH6 5900 6900
MARS 7900 9100
KU-BAND 12000 15000
13MM 1600026000

Correlator configuration

Select a correlator configuration from the menu. Only a few are listed and if yours is not listed, select NULL and enter it once you arrive at the observatory. A full list of supported modes is available from the Parkes Correlator Guide. DFB3/DFB4 configurations with "tb" indicate time-binning modes. For these, the number of time bins (set on the TCS GUI) must be at least 4 and at most 32. As an example, if you want 1 second sampling with sdfb3_tb16_16_8192, you would set the number of time-bins to 16. Other DFB3/DFB4 configurations are "spectrometer" modes and require a cycle-time more than 4s and the number of time-bins set to 1.

Correlator cycle time

Select the number of seconds per correlator cycle. If using the Multibeam Correlator, the default is 5 seconds per integration. If using DFB3 or DFB4, the cycle time depends on the configuration (especially if you are using a time binning mode), but is usually set to 4 or more.

Frequency switching

Enable frequency switching, with the switched IF separated from the main IF by some number in MHz (+ and - signs acceptable). Beware not to have an offset switch out of band.

Parallactification mode (Multibeam receivers only)

Enable receiver rotation with Multibeam receivers. For single-beam receivers, set this to disable. The modes are:

In the STEPPED mode, the platform is rotated just before a scan starts, so it is exactly in the right orientation at mid-scan. BEAMTRK does a position tweak every 5 seconds during a scan, ensuring that the platform stays close to the scan axis all the time (good for scans near the south pole). BEAMTRK is essentially the same as CONTINUOUS, but with the addition that it does the hard work of determining the actual track on the sky during a scan, and positioning the platform relative to that axis (rather than the latitude lines, for example).

Position/Feed angle

Rotate the receiver by a given angle, in degrees. This is only available with Multibeam receivers. For single-beam receivers this should be set to "0".

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.

Radial Velocity

The radial velocity of your source. Also choose the reference frame, LSR-KINEMATIC, LSR-DYNAMIC, Barycentric or Topocentric. The radial velocity information provided here will be ignored if Doppler tracking is disabled. Note: If Doppler tracking is disabled 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.

Integration time per ON position

Integration time on your source in seconds for each individual track. The corresponding reference (OFF) track 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.

Spectral averaging interval

Number of seconds to average spectra over before writing to disk. Default is no averaging (1s). However, for high data rates averaging is recommended.

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. Note it is possible to disable this by selecting the "disabled" option. The schedule only only contain ON positions.

Duration of Schedule

Total duration of the observing pattern in minutes. This 'total time' does not include driving times. This number determines the number of ON-OFF pairs. For example, if you wish to observe ON-source for 240 seconds, to observe the ON/OFF positions once (regardless of the pattern chosen), you would enter 8 minutes. To obtain four ON/OFFs, enter 16 minutes and so on.

Coordinate system

The coordinate system of your coordinates. You may choose between equatorial (J2000 or B1950) or Galactic coordinates.

Source Parameters

You can specify the name of your source here. If left blank the source name defaults to "source". For TRACK mode, you can enter your source list, one per line. Format is Name, RA/GLONG, DEC/GLAT and VELOCITY1 and VELOCITY2 (for two-IF modes). For coordinates, ensure you select the appropriate Coordinate system above. If using doppler tracking (i.e., your velocities are non-zero), ensure you set the correct frame above.

Example: AG356.48+0.19 17:36:13.8088 -31:49:06.713 -50

Offset of the ON relative to source

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

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.

Reference (OFF) Position Type

Scanning modes: You may choose only absolute positioning for the reference position.

Reference (OFF) Position Value

The position of the reference integration (2 values separated by a comma). Please take care of the format: Equatorial, RA: hh:mm:ss DEC: dd:mm:ss, Galactic GLON: ddd.xxxxx GLAT: dd.xxxxx.

Map Width

Scanning modes: The size of the map in arcmin. Only square maps are supported at this stage. The maps always have an odd number of rows so that one row passes through the map centre. Consequently the final map width may vary from what you specified here.

Scanning direction

Scanning modes: Scanning direction of the map. You may choose to perform your map along RA/GLONG (i.e. horizontal direction) or along DEC/GLAT (vertical direction). Scanning at arbitrary angles is currently not supported.

Starting point

Scanning modes: Starting point of the map. Values may be the north-eastern, north-western, south-eastern, or south-western corner.

Nyquist Frequency:

Scanning modes: This frequency value (in MHz) is used to calculate the Nyquist sampling rate for the scanning. Default is the value given in Observing Frequency.

Time spent on OFF scans:

Time spent on OFF scans in seconds. Default is calculated from the time spent on each row. Please seek advice from support staff if you require no reference scans.

Spacing between rows:

Scanning modes: Spacing in arcsec betwen rows (orthogonal to the scanning direction). Default is calculated from the Nyquist frequency using an extra 0.9 oversampling factor and a 2" guard band to mitigate against tracking errors.

Beam Size

Scanning modes: Beam size in arcsec (FWHM). Default is calculated from the Nyquist/Observing frequency with a Nyquist sampling rate (lambda/2D, where D=55m or D=64m). This value is then used to determine the scan rate.


If calmode=SYNC, TCS will enable the Cal Control Unit (CCU) so that a cal signal is turned ON. If calmode=OFF, TCS will disable the cal signal via the CCU.

Enable Tsys Logging?

If "Yes" is selected, the Tsys is calculated using the Parkes Conversion System and recorded into the RPFITS headers. For Multibeam correlator use, select "No" as this correlator drives its own Tsys online calibration.

Standing wave mitigation?

With this option, only currently offered with the 13MM reciever, assists in the mitigation of the 5MHz standing wave between the underside of the focus cabin and the dish surface. The receiver translator is moved +/- lambda (cm) within the given (integer) integration time.

New file for every source?

When TCS encounters a closef, it will close the current file. This is useful for multiple sources which can be matchd via filename with data processing applications such as ASAP and LIVEDATA.

Original: Juergen Ott (11-July-2005)
Modfied: Kate Brooks (10-Mar-2009)
Adapted for Parkes: Stacy Mader (17-July 2009)
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