What's the difference between Antenna1 and Antenna2? Axis definitions in plotms
Plotms is a powerful tool for visualizing your measurement set, and provides you with lots of choices for X- and Y- Axes. It's not always clear what the choices mean, so below are some explanations.
Scan
The scan number, as listed by listobs.
Field
The field number, as listed by listobs. Typically, each source should have a different field number.
Time
The time at which the visibility was observed, given in terms of calendar year (yyyy/mm/dd/hh:mm:ss.ss)
Time_interval
???
Is this integration time?? In what units??
???
Spw
The spectral window number (analogous to what VLA users know as an IF). The characteristics of each spectral window are listed in listobs.
Channel
The frequency channel number.
Frequency
Frequency in units of GHz. The exact definition of this frequency can be set by parameters in the Trans tab of plotms.
Corr
Correlations (e.g., RR, LL), which have been assigned integer IDs
???
By what scheme???
How can one find out what integer corresponds to which correlation???
Antenna1
For plotting baseline-based quantities like amplitude, either Antenna1 or Antenna2 must be chosen. Antenna1 is the first antenna in a baseline pair; for example, for baseline 2-4, Antenna1 = 2.
Antenna2
For plotting baseline-based quantities like amplitude, either Antenna1 or Antenna2 must be chosen. Antenna2 is the second antenna in a baseline pair; for example, for baseline 2-4, Antenna2 = 4.
Antenna
For plotting antenna-based quantities like elevation, use just plain Antenna.
Baseline
The baseline number, where baseline number is defined as ???
???
UVDist
UVDist_L
Projected baseline separations in units of the observing wavelength (lambda, not kilolambda).
U
V
W
Velocity
Amp
Phase
Real
Imag
Flag
Azimuth
Elevation
HourAngle
ParAngle
Ant-Azimuth
Ant-Elevation
Ant-ParAng
Row
FlagRow
