pipeline.extern.sensitivity_improvement

Functions

onlineChannelAveraging(vis, spw[, mymsmd])

For Cycle 3-onward data, determines the channel averaging factor from the ratio of the effective channel bandwidth to the channel width.

sensitivityImprovement(vis, spw, newchanwidth)

Computes the expected factor of improvement in sensitivity expected when making images of ALMA data with channel widths wider than the observed width. vis: name of measurement set spw: single spw index (integer) newchanwidth: width of image channel in units of the uvdata channel width, or a string with any common frequency units (‘MHz’ etc.) or ‘km/s’ useCAS8534: if True, use the approximate formula developed for the imaging pipeline; if False, use a spline fit to the integral table of values (1,2,4,8,16) cubechanwidth: if specified, then compute the improvement with respect to this chanwidth (which might be larger than the observed chanwidth). Units: Width of image channel in units of the uvdata channel width, or a string with any common frequency units (‘MHz’ etc.) or ‘km/s’ -Todd Hunter.

windowFunction([window, channelAveraging, …])

Print the FWHM and Effective sensitivity bandwidth of each of the ALMA correlator window functions, or return the value for a specific choice. The values are taken from the tables in Richard Hills’ note of April 8, 2012. window: one of [‘’, ‘uniform’,’hanning’,’welch’,’cosine’,’hamming’,’bartlett’, ‘blackmann’,’blackmann-harris’] ‘’=prints the whole table channelAveraging: 1, 2, 4, 8, or 16; >16 will return channelAveraging, other values will be spline interpolated returnValue: ‘FWHM’ or ‘EffectiveBW’ or ‘dictionary’ splineDegree: passed as the k parameter to scipy.interpolate.UnivariateSpline splineSmoothing: passed as the s parameter to scipy.interpolate.UnivariateSpline ratio: if True, then divide by the channelAveraging factor useCAS8534: uses the approximate formula developed for the pipeline rather than a spline spwchan: number of channels in spw (only used if useCAS8534=True) nchan: number of channels being combined (only used if useCAS8534=True) Returns: The effective number of native channels supplied by a single channel. -Todd Hunter.