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Basic Information on uvfft
Task: uvfft
Purpose: Fourier transform a sequence of selected uv-data.
Categories: uv analysis
UVFFT takes a 1-D Fourier transform of a uv-data sequence.
If the sequence is a time series, then the FFT is a fringe
rate spectrum. If the sequence steps the delay center, then
the FFT is a bandpass.
Key: vis
The input UV dataset name. No default.
Key: select
This selects the data to be processed, using the standard uvselect
format. Default is all data. Selecting more than one baseline
does not make much sense.
Key: line
Standard linetype of data to be tranformed, in the form:
type,nchan,start,width,step
where type can be `channel' `wide' or `velocity'.
The default is wide,2,1,1,1. The maximum number of channels
which can be processed is 8.
Key: size
The length of the sequence for the Fourier transform.
uv-data points in excess of the size of the transform are omitted.
Must be a power of 2. The default is 128.
Key: log
The list output file name. The default is the terminal.
Key: device
standard PGPLOT device, e.g. /xw
Key: delay
Step size for stepped delay center. FFT is bandpass function.
Default=0 Delay center not stepped. FFT is fringe frequency spectrum.