Initial setup¶

Antenna overall setup¶

When opening a DISCOS observing session, it is necessary to perform a setup which includes the antenna unstow, the mount configuration in tracking mode, the minor servo setup. This is done by means of a unique command, which is specific for the wanted receiver, to be written in the operatorInput. The currently available choices are:

> setupLLP  for the L band receiver (Primary focus)
> setupPPP  for the P band receiver (Primary focus)
> setupCCB  for the C band receiver (BWG focus)
> setupKKG  for the K band receiver (Gregorian focus)


Note

Spaces within the command line content are not allowed!

The above setup command sets the antenna mount, the minor servos, the selected receiver and the default backend (TotalPower) according to default parameters. The antenna mode is set to ProgramTrack (allowing tracking and the execution of schedules), while the Local Oscillator frequency and the bandwidth are set as illustrated in the following table.

Receiver LO freq Frontend IF band Backend IF band Observed bandwidth Observed band
code (MHz) (MHz) (MHz) (MHz) (MHz)
LLP (0) 1300-1800 (50-2350) [1] 500 (1300-1800) [1]
PPP (0) 305-390 (50-730) [1] 85 (305-390) [1]
CCB 5600 100-2100 50-2350 2000 5700-7700
KKG 21964 100-2100 50-2350 2000 22064-24064
 [1] (1, 2, 3, 4) Still subject to variations

Notice that, depending on the devices in use, the sky frequency at the observed band starting point is given by the LO frequency plus an offset. For the present combinations of the frontends with the total power backend, which the above table refers to, this offset is 100 MHz. In general, the true observed band depends on the intersection between the frontend IF band and the chosen backend filter. The actual observed bandwidth and the band starting frequency are recorded in the output files (see Appendix C - Output files).

Active Surface setup¶

After the initial setup, to configure and enable the active surface (AS) give the following commands in the operatorInput panel:

> asSetup=[code]


where [code] is:

• SF shaped configuration in fixed position (optimised for El=45°)
• S shaped configuration in tracking – i.e. it adjusts according to the observed elevation position
• PF parabolic configuration in fixed position (optimised for El=45°)
• P parabolic configuration in tracking – i.e. it adjusts according to the observed elevation position

Warning

Check the AS status! In case the system - or just the AS - was rebooted, pay attention to give the asSetup command only once all the AS actuators are online and ready. You can check this condition in the GUI shown below. Red pixels in the graphical representation of the AS indicate off-line actuators, while green pixels identify the on-line actuators.

Minor Servo configuration¶

When using the Gregorian or BWG focus only, the Antenna overall setup automatically configures the minor servo system in order for the elevation to be tracked, and assumes the active surface is enabled. That means the minor servo setup automatically issues the following commands:

> setServoElevationTracking=ON
> setServoASConfiguration=ON


The user is asked to issue the correct configuration in case other behaviours are required.

Logfile and project code¶

The default logfile is named station.log. If the user wants to change it:

> log=[logfilename]  (without extension)


Logfiles are stored in a dedicated folder (see Retrieving the data). When schedules are run, a new logfile is automatically started, and it is named after the schedule: [schedulename].log.

It is possible, and advisable, to insert the project code/name (a string assigned to the project by the TAC) using the command:

> project=[projectcode]   (e.g. project=scicom)


This will make the user save time in later stages, as it will not be necessary to specify the project name in schedule-launching commands. The project code/name must correspond to an existing user, already known to the system. This means that, if its spelling does not match with the recorded name, an error rises.