Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Timing X-ray Pulsars with Application to Spacecraft Navigation   Usually, positions of spacecraft on interplanetary or deep space missions are
determined by radar tracking from ground stations, a method by which
uncertainty increases with distance from Earth. As an alternative, a spacecraft
equipped with e.g. an X-ray telescope could determine its position autonomoulsy
via onboard analysis of X-ray pulsar signals. In order to find out which
pulsars are best suited for this approach and what accuracy can be achieved, we
build up a database containing the temporal emission characteristics of the ~
60 X-ray pulsars for which a pulsed radiation has been detected by mid 2010.

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The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom