Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

These are available as fits files as well as quick-look png images.

The structure of the Continuum image MFS cube fits file is not standard. A more complete description of its structure can be found in Section V Data Products of this document http://www.cv.nrao.edu/~bcotton/ObitDoc/MFImage.pdf, which describes the MFImage imager used by the SDP continuum imaging pipeline. In brief the image consists of multiple planes which are:

1) A plane in which the pixel values are the flux densities at the image reference frequency.
2) A spectral index plane of the fitted spectral index
4) A cube of of roughly constant fractional bandwidth subband images which are not equally spaced in frequency.
The lower and upper edges of the frequencies of the subband images are indicated by the FRELnnn and FREHnnnn parameters in the fits header for the nnnnth subband (1 relative). The centre frequency is indicated by the FREQnnnn parameter and the NSPEC parameter gives the number of subband image planes following the spectral planes

...

Spectral images

...

Each spectral channel is imaged independently, with image parameters optimised for that particular frequency. Each plane can be downloaded independently.

...