Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring CMB polarisation with the Planck mission   In this paper, we discuss why and how the Planck mission, originally designed
and proposed for mapping CMB intensity fluctuations, has been revised for
polarisation measurement capability as well.

19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin