Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: S4: A Spatial-Spectral model for Speckle Suppression   High dynamic-range imagers aim to block out or null light from a very bright
primary star to make it possible to detect and measure far fainter companions;
in real systems a small fraction of the primary light is scattered, diffracted,
and unocculted. We introduce S4, a flexible data-driven model for the
unocculted (and highly speckled) light in the P1640 spectroscopic coronograph.
The model uses Principal Components Analysis (PCA) to capture the spatial
structure and wavelength dependence of the speckles but not the signal produced
by any companion. Consequently, the residual typically includes the companion
signal. The companion can thus be found by filtering this error signal with a
fixed companion model. The approach is sensitive to companions that are of
order a percent of the brightness of the speckles, or up to $10^{-7}$ times the
brightness of the primary star. This outperforms existing methods by a factor
of 2-3 and is close to the shot-noise physical limit.

12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
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The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
2
The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: physics