in astronomy, what is a datacube?

Question

in astronomy, what is a datacube?

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Answer 1

Consider a greyscale digital photograph; this is effectively a square of data with each pixel having a brightness value.

Now consider an RGB digital photo; this is three squares of brightness values one for each colour channel.

Now imagine you have full spectral data for each pixel. Instead of one brightness value you have one for each point along the spectrum: thousands of squares stacked on top of each other.

So this is the data cube, one dimension is X, one is Y, the other is wavelength/frequency. The value of each datapoint is the brightness. Technically we don’t call each position a pixel but a spaxel, at least in my instrument.

I’d imagine that there are other datasets that could be formatted in this way.