Dedisperses filterbank format data. Supports flipped-band data, as well as non-quadratic dispersion correction. The following file types are supported:

• DAS .spec filterbank format
• SIGPROC .fil filterbank format (including the headerless version, provided a .fhd configuration file is present in the same directory)

The output may be written as one of DAS .dds, SIGPROC .tim, or a non-frequency-collapsed SIGPROC .fil. In the case of the latter, irrespective of the original format of the data, the output samples are single-precision floats. The start MJD of the output reflects dispersion delay correction with respect to infinite frequency.

Sub-band dedispersion is also supported, but only one sub-band at a time.

Usage:

• -h or --help: Display this usage information.
• -s or --skip time: Length of data to be skipped, in seconds (default is 0 s).
• -p or --proc time: Length of data to be processed, in seconds (default is all data).
• -n or --nsamp samples: Number of time samples read in one block (default is 4096 samples).
• -d or --dm dm: DM at which to dedisperse (default is 0.0).
• -l or --law law: Dispersion law (default is 2.0).
• -b or --nsubband nsubband: Number of sub-bands (factor of number of channels, must be < number of channels)
• -u or --subband subband: Sub-band to dedisperse (within [0, nsubband))
• -o or --out-format format: Output format - 'dds', 'tim', or 'fil' (default is 'tim').
• -g or --graphics: Turn on plotting.
• -m or --colour-map name: Colour map for plotting. Supports some of the standard MATLAB colour maps, plus a few more. Valid colour map names are given below (default is 'jet').
  • 'autumn'
  • 'blue'
  • 'bone'
  • 'cool'
  • 'copper'
  • 'gray'
  • 'gray-inv'
  • 'hot'
  • 'hot-inv'
  • 'jet'
  • 'pink'
  • 'spring'
  • 'summer'
  • 'winter'
  • 'RdBu'
  • 'BuRd'
• -i or --invert: Invert background and foreground colours in plots (default is white on black).
• -e or --non-interactive: Run in non-interactive mode.
• -v or --version: Display the version.

Example:

Dedisperse the data in data.fil with a DM of 13.2952, with graphics turned on, and in non-interactive mode. The output is written to data.dm13.2952.tim.

Treat the 1024-channel filterbank data in data.fil as being made up of 16 sub-bands, and dedisperse the first 64-channel sub-band (lowest in frequency) with a DM of 13.2952, with graphics turned off. It is assumed that the band is not flipped. The output is written to data.dm13.2952.band0.tim.