  This paper studies how to employ synchrotron emission gradient techniques to
reveal the properties of the magnetic field within the interstellar media.
Based on data cubes of three-dimensional numerical simulations of
magnetohydrodynamic turbulence, we explore spatial gradients of synchrotron
emission diagnostics to trace the direction of the magnetic field. According to
our simulations, multifarious diagnostics for synchrotron emission can
effectively determine the potential direction of projected magnetic fields.
Applying the synergies of synchrotron diagnostic gradients to the archive data
from the Canadian Galactic Plane Survey, we find that multifarious diagnostic
techniques make consistent predictions for the Galactic magnetic field
directions. With the high-resolution data presently available from Low
Frequency Array for radio astronomy and those in the future from the Square
Kilometer Array, the synergies of synchrotron emission gradients are supposed
to perform better in tracing the actual direction of interstellar magnetic
fields, especially in the low-frequency Faraday rotation regime where
traditional synchrotron polarization measure fails.
