Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Night Sky Background Analysis for the Cherenkov Telescope Array using
  the Atmoscope instrument   The site selection group for the future Cherenkov Telescope Array (CTA) has
deployed sensitive light sensors at 9 candidate sites, 5 of them in the
Southern and 4 in the Northern hemisphere. The sensors are equipped with a PIN
diode and a calibrated V-filter, and a blue/UV filter matching the spectral
response of the photomultipliers to be employed in the CTA cameras. All sensor
installations, denominated "Atmoscopes", have been cross-calibrated before
deployment, and their sensitivity is monitored every two to five months. We
show that a thoroughly developed model of the integral contribution of
starlight to the overall light measure serves as an additional
cross-calibration for each device during each night, reducing the systematic
uncertainty of this measurement to less than 15%. The starlight can then be
subtracted from the measurements, and the residuals compared among the
different sites. We show that in most cases a decomposition into the
contributions from zodiacal light, airglow and anthropogenic light pollution is
possible.

8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph