Radio Astronomy Use cases:
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Use Case: Search for spectral emission or absorption line, e.g., search for water maser features in a star formation region, blind search for Ly-alpha emitters; specific examples related to projects include SDSS and ASKAP/FLASH
Need:  3-D image cube consisting of 2 space and 1 frequency/velocity axes, with ability to search in frequency/velocity at every spatial pixel

Show me a list of data that satisfies:
I. Datatype=cube with 3 dimensions
II. Axes include Frequency
III. Axes include RA
IV. Axes include DEC
V. Frequency range includes 22 GHz 
VI. (from ability requirement) spectral emission feature detected on frequency axis

Use Case: Search for polarized emitter, e.g., sky survey for Faraday rotation
Need: 3-D image cube consisting of 2 space and 1 polarization axes, with ability to search for or extract polarization at every spatial pixel; specific examples related to projects include ASKAP/POSSUM
polarization probably most naturally stored as Stokes parameters, but other representations should also be allowed (e.g., XX, YY, XY, YX or RR, LL, RL, LR)

Show me a list of data that satisfies:
I. Datatype=cube with 3 dimensions
II. Axes include polarization (XX, YY, XY, YX or RR, LL, RL, LR)
III. Axes include RA
IV. Axes include DEC 

Use Case: Search or monitor time variable phenomena, e.g. intra-day variability, stellar pulsations, long-term stellar variability, AGN or galaxy central engine variability; specific examples related to projects include the Palomar Transient Factory, Skymapper, Pan-STARRS, ASKAP/VAST, and LSST
Need: 3-D image cube consisting of 2 space and 1 time axes, with ability to search for and extract on time axis

Show me a list of data that satisfies:
I. Datatype=cube with 3 dimensions
II. Axes include time
III. Axes include RA
IV. Axes include DEC
V. (from ability requirement) pulsations or variability detected along time axis

Use Case: Search for polarized spectral line signatures, e.g., Zeeman splitting
Need: 4-D image cube consisting of 2 space, 1 polarization axis, and 1 spectral axis, with ability to search for and extract polarization signatures as a function of frequency/velocity for every pixel in the image

Show me a list of data that satisfies:
I. Datatype=cube with 4 dimensions
II. Axes include polarisation
III. Axes include frequency
IV.  Axes include RA
V. Axes include DEC
VI. (from ability requirement) Pixels where polarization signatures detected as a function of frequency

Use Case: Search for polarized time-dependent phenomena, e.g., intra-day variability; potential specific example includes ASKAP/VAST
Need: 4-D image cube consisting of 2 space, 1 polarization, and 1 time domain axis, with ability to search for and extract polarization signatures as a function of time for every pixel in the image

Show me a list of data that satisfies:
I. Datatype=cube with 4 dimensions
II. Axes include polarisation
III. Axes include time
IV.  Axes include RA
V. Axes include DEC
VI. (from ability requirement) Pixels where polarization signatures detected as a function of frequency

Use Case: Search for time-dependent spectral lines, e.g., maser flares, variable AGN emission lines, variable narrow X-ray absorption line systems; potential specific example includes ASKAP/VAST
Need: 4-D image cube consisting of 2 space, 1 spectral axis, and 1 time domain axis, with ability to search for and extract spectral signatures as a function of time for every pixel in the image

Show me a list of data that satisfies:
I. Datatype=cube with 4 dimensions
II. Axes include frequency
III. Axes include time
IV.  Axes include RA
V. Axes include DEC
VI. (from ability requirement) pixels where spectral signatures are detected

Use Case: Search for time-dependent polarized spectral line signatures, e.g., time variable Zeeman splitting? intra-day variability induced changes in spectral lines?
Need: 5-D image cube consisting of 2 space, 1 spectral axis, 1 time domain axis, and 1 polarization axis, with ability to search for and extract along any one axis as a function of another

Show me a list of data that satisfies:
I. Datatype=cube with 5 dimensions
II. Axes include frequency
III. Axes include time
IV. Axes include polarization
V.  Axes include RA
VI. Axes include DEC