Post-Acquisition Beam Forming

New in version 0.3.

Module to allow for post-acquisition delay-and-sum beamforming with TBW and TBN data using both integer sample delays for time series data (intDelayAndSum) and fractional delays for time series data transformed to the frequency domain (fftDelayAndSum). fftDelayAndSum is still under development.

exception lsl.misc.beamformer.BeamformingError(strerror, errno='-1')

Base class for all exceptions in this file.

lsl.misc.beamformer.calcDelay(stands, freq=49000000.0, azimuth=0.0, elevation=90.0)

Calculate the time delays for delay-and-sum beam forming a collection of stands looking in at a particular azimuth and elevation (both in degrees). A numpy array of the geometric + cable delays in seconds is returned.

lsl.misc.beamformer.intDelayAndSum(stands, data, sampleRate=196000000.0, azimuth=0.0, elevation=90.0)

Given a list of stands and a 2-D data stream with stands enumerated along the first axis and time series samples along the second axis, delay and sum the data stream into one beam. The delays applied are integer sample delays. Return a 1-D numpy array of the time series data associated with the formed beam.

lsl.misc.beamformer.intBeamShape(stands, sampleRate=196000000.0, azimuth=0.0, elevation=90.0, progress=False, DisablePool=False)

Given a list of stands, compute the on-sky response of the delay-and-sum scheme implemented in intDelayAndSum. A 360x90 numpy array spaning azimuth and elevation is returned.

lsl.misc.beamformer.fftDelayAndSum(stands, data, sampleRate=196000000.0, LFFT=256, CentralFreq=49000000.0, azimuth=0.0, elevation=90.0)

Given a list of stands and a data stream of the form stands x times, delay and sum the data stream into one beam. The delays first applied as integer sample delays. Then, the data are transformed to the frequency domain and the remainder of the delay is applied as a phase rotation. A tuple consisting of the frequency array and a numpy array of the frequency-domain data over time is returned.

lsl.misc.beamformer.fftBeamShape(stands, sampleRate=196000000.0, LFFT=256, CentralFreq=49000000.0, azimuth=0.0, elevation=90.0, progress=False)

Given a list of stands, compute the on-sky response of the delay-and-sum scheme implemented in intDelayAndSum. A 360x90 numpy array spaning azimuth and elevation is returned.