# AIPS HELP file for BASELINE in 31DEC18

### HELP SECTION

```BASELINE
Use:  Standard data selection adverb, used in conjunction with
ANTENNAS to specify baseline selection.
Null Value:  0
All null value means use all antennas.

BASELINE is always used with ANTENNAS.  In that case, a baseline
between antenna I and J is selected (or deselected if any of
ANTENNAS or BASELINE are negative) if
# in ANTE     # in BASE     Selected or de-selected if
0             0        always
>0             0        (I in ANTE) .OR. (J in ANTE)
0            >0        (I in BASE) .OR. (J in BASE)
>0            >0        ((I in ANTE) .AND. (J in BASE)) .OR.
((I in BASE) .AND. (J in ANTE))

Verbs VLA, EVLA, VLBA, and HSA may be used to set values into
BASELINE (or any other adverb array).  In this case, the equals
sign is required, e.g.,
ANTENNAS = EVLA
BASELINE = VLA
to process all baselines between new EVLA and old VLA antennas.
Be careful of INNAME et al., SUBARRAY, and DOINVERS which
control what these verbs actually do.

Examples:
1. BASELINE=0; ANTENNAS=0
include everything
2. BASELINE=0; ANTENNAS=1,2,3,4,5,6
include only baselines between antennas 1 through 6
3. BASELINE=0; ANTENNAS=1,2,-3,4,5,6
include only baselines between antennas 7 through N
4. BASELINE=0; ANTENNAS = 11,-19,27
exclude any baseline involving antennas 11, 19, and/or 27
thus, exclude 1-11, 7-19, 11-19, 26-27, etc. etc.
5. BASELINE=1,2,7; ANTENNAS=3,4,5
include baselines 1-3, 1-4, 1-5, 2-3, 2-4, 2-5, 3-7,
4-7, 5-7 only
6. BASELINE=1,-2,7; ANTENNAS=3,4,5
include all baselines except 1-3, 1-4, 1-5, 2-3, 2-4, 2-5,
3-7, 4-7, 5-7
7. BASELINE=-10; ANTENNAS=-10
exclude baseline 10-10 (autocorrelation), include all other
baselines including those to antenna 10.
```

AIPS