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SOLVE RF_PASSBAND
CLIC\SOLVE RF_PASSBAND [da] [dp] [/PLOT]
*** THIS HELP HAS NOT BEEN UPDATED FOR THE NGRX ***
Solve for passband calibration curves, by fitting it to the amplitudes and
phases. The current index should contain calibration observations of
strong continuum sources (RF passband calibrator). The behaviour of this
command depends on the current mode of RF passband calibration (Frequency
or Channel).
- For frequency-dependent RF passabnd calibration (SET RF_PASSBAND FRE-
QUENCY, recommended): the resolution is normally done using all the
spectral subbands plotted together, as a function of intermediate fre-
quency. It should be done separately for upper and lower side bands. A
single frequency-dependent polynomial is fitted, a high degree might
be necessary for the phase, if band edges are used (up to 20 is feasi-
ble).
- For channel dependent RF passband calibration (SET RF_PASSBAND CHAN-
NEL)
(i) For continuum, the data itself is directly stored as calibration
values (this gives a channel-dependent passband curve). In addition a
polynomial is fitted and optionally plotted (this gives a frequency-
dependent passband curve).
(ii) For spectral subbands, polynomials are fitted and optionally
plotted, as a channel-dependent passband curve.
The degrees for polynomials are 'da' for amplitude, 'dp' for phase (de-
faults 0 and 1). Command STORE should be used next to store the fitted
function in the header of source observations. Both channel dependent and
frequency dependent curves can be stored; Use command SET RF_PASSBAND FRE-
QUENCY|CHANNEL to apply one or the other.
Option /PLOT will plot the polynomial fits over the data.
Gildas manager
2011-09-07