Manpage of linecal
Section: User Commands (1)
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linecal - Estimate antenna gains from line length measurements.
LINECAL is a Miriad task to estimate the instrumental phase
drifts due to line length changes. The measured phases are
written as antenna gains and can be manipulated and displayed
using the GP routines and BEE. The resulting gains can be plotted
with GPPLT and smoothed to reduce the noise with GPAVER.
The gains for bad line length phases can be edited with GPEDIT,
or with BEE if you want to do fancy things.
The line length gains are applied when copying or plotting
NOTE: the linelength data are stored as an antenna based
UV variable called phasem1, in radians. But note that this
variable is not removed by any subsquent uvcat, and applying
linecal twice is probably not a good thing.
Name of input visibility data file. No default.
The visibility data must be in time order.
Optional name of the output calibration file.
The default is to write the gain corrections into the input
Optional Frequency (in GHz) to use to convert a cable (in ms)
measurement (in ns) to phasem1 (in radians) for linelength.
Normally this option is not used, since phasem1 was derived
by using the LO1 frequency. This option has been added for
debugging the cable to phasem1 conversion.
Usually this option does not make sense for CARMA as LO1 is
doppler tracked and this freq= would not be. For SZA this is
appropriate, as they do not doppler track.
For SZA data freq=35.938 should be used.
Default: not used, and phasem1 is used to build the gain table.
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This document was created by
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Time: 18:35:38 GMT, July 05, 2011