  Probing magnetic fields in astrophysical environments is both important and
challenging. The Gradient Technique (GT) is a new tool for tracing magnetic
fields, rooted in the properties of magnetohydrodynamic (MHD) turbulence and
turbulent magnetic reconnection. In this work, we examine the performance of GT
when applied to synthetic synchrotron emission and spectroscopic data obtained
from sub-Alfv\'enic and trans-Alfv\'enic MHD simulations. We demonstrate the
improved accuracy of GT in tracing magnetic fields in the absence of
low-spatial frequencies. Additionally, we apply a low-spatial frequency filter
to a diffuse neutral hydrogen region selected from the GALFA-\ion{H}{1} survey.
Our results show an increased alignment between the magnetic fields inferred
from GT and the Planck 353 GHz polarization measurements.
