VLAMODE

VLAMODE is used to control phasing up of the VLA. The control can also be done directly by specifying the phasing related INTENTs, but that can be more cumbersome, especially if other INTENTs are changing from scan to scan. A phasing mode is required. For a schedule using the VLA, if SCHED  does not get a VLAMODE or a phasing related INTENT, it will quit. When VLAMODE is used, SCHED will generate the appropriate INTENTs for the VEX file for the VLAMODE that is given.

VLA reference pointing and array phasing must not be requested in the same scan.

The valid VLAMODE values are:

' ' - Do not apply or determine phases. This generates INTENT = VLA:AUTOPHASE_OFF.

'VA' - auto phasing on all IFs. This generates INTENT = VLA:AUTOPHASE_DETERMINE.

'VX' - Apply phasing determined in previous VA scan.) This generates INTENT = VLA:AUTOPHASE_APPLY.

'VS' - single antenna VLBI (not available on EVLA as of Jan. 2013). May want this to keep the phase center at the antenna if at all possible. This could generate INTENT = VLA:SINGLE_DISH.

• Argument: Text of 2 characters.
• Options: See list above.
• Default: None - required for VLA.
• Usage: Defaults to previous scan.
• Example: VLAMODE='VX'