Spectral Line Calibration and Imaging
Anita Richards
- How narrow-band data are obtained
- Telescope user information should describe the available frequency
- ranges, restrictions include
- available receivers
- LO settings
- filters Probably don't have to worry about the details unless you want to observe very close to the edge or are trying to avoid RFI
- Restrictions on how many sub-bands (IFs), band-width and channel-width
- example correlator configs
- polarizations, data rates etc.
- Telescope user information should describe the available frequency
- Fixed freq. v. fixed Vlsr
- velocity conventions
- Designing bandpass calibration
- Phase-refs/fringe finders observed in different modes
- Walk-through typical examples:
- techniques to be covered
- bandpass calibration
- applying calibration between data at different frequencies
- LSR corrections
- finding the line (faint, off-centre etc.)
- selfcal
- techniques to be covered
- Line Data Sets
- MERLIN water masers - line data plus bandpass calibration
- MERLIN OH full polarization including
- wide-narrow band offsets
- preserving Stokes V in self-cal
- EVN methanol masers
- HI absorption+continuum
- Imaging and analysis techniques
- Using prior knowledge
- Tests for fidelity
- ringing
- confusion/wide fields (where off-centre sources are lines)
- extraction of spectra
- Chosing weighting/resolution suitable for source characteristics
- driving SAD
- other post-processing e.g. linear polarization parms