Faster imaging simulation through complex systems: a coronagraphic example. (arXiv:2106.09122v1 [astro-ph.IM])
<a href="http://arxiv.org/find/astro-ph/1/au:+Milani_K/0/1/0/all/0/1">Kian Milani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Douglas_E/0/1/0/all/0/1">Ewan S. Douglas</a>
End-to-end simulation of the influence of the optical train on the observed
scene is important across optics and is particularly important for predicting
the science yield of astronomical telescopes. As a consequence of their goal of
suppressing starlight, coronagraphic instruments for high-contrast imaging have
particularly complex field-dependent point-spread-functions (PSFs). The Roman
Coronagraph Instrument (CGI), Hybrid Lyot Coronagraph (HLC) is one example. The
purpose of the HLC is to image exoplanets and exozodiacal dust in order to
understand dynamics of solar systems. This paper details how images of
exoplanets and exozodiacal dust are simulated using some of the most recent
PSFs generated for the CGI HLC imaging mode. First, PSFs are generated using
physical optics propagation techniques. Then, the angular offset of pixels in
image scenes, such as exozodiacal dust models, are used to create a library of
interpolated PSFs using interpolation and rotation techniques, such that the
interpolated PSFs correspond to angular offsets of the pixels. This means
interpolation needs only be done once and an image can then be simulated by
multiplying the vector array of the model astrophysical scene by the matrix
array of the interpolated PSF data. This substantially reduces the time
required to generate image simulations by reducing the process to matrix
multiplication, allowing for faster scene analysis. We will detail the steps
required to generate coronagraphic scenes, quantify the speed-up of our matrix
approach versus other implementations, and provide example code for users who
wish to simulate their own scenes using publicly available HLC PSFs.
End-to-end simulation of the influence of the optical train on the observed
scene is important across optics and is particularly important for predicting
the science yield of astronomical telescopes. As a consequence of their goal of
suppressing starlight, coronagraphic instruments for high-contrast imaging have
particularly complex field-dependent point-spread-functions (PSFs). The Roman
Coronagraph Instrument (CGI), Hybrid Lyot Coronagraph (HLC) is one example. The
purpose of the HLC is to image exoplanets and exozodiacal dust in order to
understand dynamics of solar systems. This paper details how images of
exoplanets and exozodiacal dust are simulated using some of the most recent
PSFs generated for the CGI HLC imaging mode. First, PSFs are generated using
physical optics propagation techniques. Then, the angular offset of pixels in
image scenes, such as exozodiacal dust models, are used to create a library of
interpolated PSFs using interpolation and rotation techniques, such that the
interpolated PSFs correspond to angular offsets of the pixels. This means
interpolation needs only be done once and an image can then be simulated by
multiplying the vector array of the model astrophysical scene by the matrix
array of the interpolated PSF data. This substantially reduces the time
required to generate image simulations by reducing the process to matrix
multiplication, allowing for faster scene analysis. We will detail the steps
required to generate coronagraphic scenes, quantify the speed-up of our matrix
approach versus other implementations, and provide example code for users who
wish to simulate their own scenes using publicly available HLC PSFs.
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