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Ask HN: Askap Dataset in Steradians/Pixel

1 pointsby macuover 4 years ago
Can someone figure out the pixel size of the new ASKAP dataset (&quot;which covers 83% of the sky, is a combination of 903 individual images, each containing 70 billion pixels&quot; [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&#x2F;pixel. (Approximation using the above values may not apply to actual dataset if steradians ranges across the images like areas delimited by latitudes&#x2F;longitudes.) Can hardly wait for the app to explore this<p>[1] https:&#x2F;&#x2F;www.livescience.com&#x2F;fastest-all-sky-map-ever-askap.html<p>[2] https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Steradian<p>Edit: changed link 2 to avoid overwhelming a small site

1 comment

macuover 4 years 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&#x2F;pixel, though there may be overlap in the images, unsure.<p>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&#x2F;pixels, so the HUDF is about an order of magnitude higher resolution.