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O12.4: Lam, Cheuk Yin
Marco C Lam (Astrophysics Research Institute, Liverpool John Moores University)






Time: Mon 14.15 - 14.30
Theme: Algorithms
Title: Data-Driven Pixelisation with Voronoi Tessellation

In modern Astrophysics, Voronoi Tessellation is a rarely used as a pixelisation scheme. While it exists, it is almost exclusively used in signal enhancements and simulations. In Observational Astronomy, with Gaia, ZTF, DES etc. data becoming available, LSST and Euclid coming online in the next decade, this branch of science is becoming more and more data-driven. HEALPix, HTM and Q3C offer excellent ways to pixelise the celestial sphere, the implementations completely separate the background information from the signal. There are excellent use cases to have them independent from each other, but there are also cases when this becomes a burden in computation when we have to process more pixels than necessary or require post-hoc calculations to group pixels at different resolution levels to form larger segments. With Voronoi Tessellation, it can generate a one-to-one mapping of data points to Voronoi cells where anywhere inside the cell is the closest to the “governing” data point. We illustrate the application of Voronoi Tessellation in a set of magnitude and proper motion-limited data how it can simplify the survey properties of the 3pi Steradian Survey from the Pan-STARRS 1, where the footprint area is imaged by the 60 CCDs at ~10^5 pointings over 3.5 years.

Link to PDF (may not be available yet): O12-4.pdf