Disperse

class baseband_tasks.dispersion.Disperse(ih, dm, *, reference_frequency=None, samples_per_frame=None, frequency=None, sideband=None)

Bases: PaddedTaskBase

Coherently disperse a time stream.

Parameters:

ihtask or baseband stream reader

Input data stream, with time as the first axis.

dmfloat or DispersionMeasure quantity

Dispersion measure. If negative, will dedisperse correctly, but clearer to use the Dedisperse class.

reference_frequencyQuantity, optional

Frequency to which the data should be dispersed. Can be an array. By default, the mean frequency.

samples_per_frameint, optional

Number of dispersed samples which should be produced in one go. The number of input samples used will be larger to avoid wrapping. If not given, the minimum length that gives at least 75% efficiency and ensures efficient fast fourier transforms.

frequencyQuantity, optional

Frequencies for each channel in ih (channelized frequencies will be calculated). Default: taken from ih (if available).

sidebandarray, optional

Whether frequencies in ih are upper (+1) or lower (-1) sideband. Default: taken from ih (if available).

See also

baseband_tasks.fourier.fft_maker

to select the FFT package used.

baseband_tasks.dispersion.Dedisperse

for coherent dedispersion

baseband_tasks.dispersion.DisperseSamples

for incoherent dispersion

Attributes Summary

dm
phase_factor	Phase offsets of the Fourier-transformed frame.

Methods Summary

close()	Close task.
task(data)

Attributes Documentation

dm

phase_factor

Phase offsets of the Fourier-transformed frame.

Methods Documentation

close()

Close task.

Note that this does not explicitly close the underlying source; instead, it just deletes the reference to it.

task(data)