(This page is currently under construction...)

Project Charter

Long Description

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1. Spectral Data Cubes, Spectral Weights, Continuum Maps, Continuum Weights

Data cube option 1 (Everything in one file - a primary header and three image headers)

    Number of files:  ~7500 data cubes

Data cube option 2 structures (Spectral cube and three ancillary products - spectral weights, continuum maps, and continuum weights). 

    Note that this " option 2" will likely fit best within the current archive scheme.

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Dimensions of the data:

    Spectral data cubes:   2 polarizations  x  1024 frequency channels   x        144 RA pixels   x 144 Decl. pixelspixels  x  1024 frequency channels   x   2 polarizations   (Example spectral line data cube)

    Spectral weights:         2 polarizations  x  1024 frequency channels   x 144      144 RA pixels   x 144 Decl. pixelspixels  x  1024 frequency channels   x   2 polarizations    (Example spectral line weights - also a cube)

    Continuum maps:        2 polarizations x       144 RA pixels   x 144 Decl. pixelspixels  x 2 polarizations   (Example continuum FITS image)

    Continuum weights:        2 polarizations x 144 RA pixels   x 144 Decl. pixelspixels  x 2 polarizations   (Example continuum weights)

Volume of data (< 10 TB)

Frequency range:  1335 to 1445 MHz (L-band)

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The expectation is that a user would search for a position on the sky, or via a galaxy name (NED resolver, etc.).     For instance, if one searches on the position 12h20m00s, +09d00m00s, four data cubes, each with three additional ancillary products, would be returned (16 totals hits, total volume would be ~ 1.6 GB). Put readthedocs here...

At the most basic level, using AstroPy, we would expect an end user to download a set of ALFALFA files and manipulate them with some simple Python or a Jupyter notebook (Example demo: ReadTheDocs)

Stakeholders

Brian Kent, NRAO, Project Sponsor and Technical Expert

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