Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Positioning and orienting a static cylindrical radio-reflector for wide
  field surveys   Several projects in radioastronomy plan to use large static cylindrical
reflectors with an extended lobe sampling a sector of the rotating sky. This
study provides the exact mathematical expression of the transit time of a
celestial object within the acceptance lobe of such a cylindrical device. The
mathematical approach, based on the stereographic projection, allows one to
study the optimisation of the position and orientation of the radio-reflector,
and should provide exact coefficients for the spatial Fourier Transform of the
radio signal along the cylinder axis.

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The categories of this paper are: quant-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
3
The categories of this paper are: physics