Ask HN: Askap Dataset in Steradians/Pixel

1 pointsmacu5y ago1 comments

Can someone figure out the pixel size of the new ASKAP dataset ("which covers 83% of the sky, is a combination of 903 individual images, each containing 70 billion pixels" [1]) in steradians [2] as well as for the Hubble Ultra Deep Field, as I am curious how to know their relative resolutions in steradians/pixel. (Approximation using the above values may not apply to actual dataset if steradians ranges across the images like areas delimited by latitudes/longitudes.) Can hardly wait for the app to explore this

[1] https://www.livescience.com/fastest-all-sky-map-ever-askap.html

[2] https://en.m.wikipedia.org/wiki/Steradian

Edit: changed link 2 to avoid overwhelming a small site

1 comments

macuOP5y ago

Approximation for the ASKAP images with help from Wolfram Alpha, .83 spheres is 10.4 steradians, so 903*70 billion is 63.21 trillion pixels, at ~1.65e-13 steradians/pixel, though there may be overlap in the images, unsure.

Approximation for HUDF is 38.44 million pixels, covering 11 square arcminutes (from Wikipedia) which is 9.308e-7 steradians at ~2.75e-14 steradians/pixels, so the HUDF is about an order of magnitude higher resolution.

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