Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A multi-method approach to radial-velocity measurement for single-object
  spectra   The derivation of radial velocities from large numbers of spectra that
typically result from survey work, requires automation. However, except for the
classical cases of slowly rotating late-type spectra, existing methods of
measuring Doppler shifts require fine-tuning to avoid a loss of accuracy due to
the idiosyncrasies of individual spectra. The radial velocity spectrometer
(RVS) on the Gaia mission, which will start operating very soon, prompted a new
attempt at creating a measurement pipeline to handle a wide variety of spectral
types.
  The present paper describes the theoretical background on which this software
is based. However, apart from the assumption that only synthetic templates are
used, we do not rely on any of the characteristics of this instrument, so our
results should be relevant for most telescope-detector combinations.
  We propose an approach based on the simultaneous use of several alternative
measurement methods, each having its own merits and drawbacks, and conveying
the spectral information in a different way, leading to different values for
the measurement. A comparison or a combination of the various results either
leads to a "best estimate" or indicates to the user that the observed spectrum
is problematic and should be analysed manually.
  We selected three methods and analysed the relationships and differences
between them from a unified point of view; with each method an appropriate
estimator for the individual random error is chosen. We also develop a
procedure for tackling the problem of template mismatch in a systematic way.
Furthermore, we propose several tests for studying and comparing the
performance of the various methods as a function of the atmospheric parameters
of the observed objects. Finally, we describe a procedure for obtaining a
knowledge-based combination of the various Doppler-shift measurements.

25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph