Statistical tracing of magnetic fields: comparing and improving the
  techniques
  Magnetohydrodynamic(MHD) turbulence displays velocity anisotropies which
reflect the direction of the magnetic field. This anisotropy has led to the
development of a number of statistical techniques for studying magnetic fields
in the interstellar medium. In this paper, we review and compare three
techniques that use radio position-position-velocity data for determining
magnetic field strength and morphology : the correlation function anisotropy
(CFA), Principal Component Analysis of Anisotropies (PCAA), and the more recent
Velocity Gradient Technique (VGT). We compare these three techniques and
suggest improvements to the CFA and PCAA techniques to increase their accuracy
and versatility. In particular, we suggest and successfully implement a much
faster way of calculating non-periodic correlation functions for the CFA. We
discuss possible improvements to the current implementation of the PCAA. We
show the advantages of the VGT in terms of magnetic field tracing and stress
the complementary nature with the other two techniques.
