  Studies of surface brightness (SB) fluctuations in the intracluster medium
(ICM) present an indirect estimate of turbulent pressure support and associated
Mach numbers. While high resolution X-ray spectroscopy offer means to directly
constrain line of sight gas motions, including those due to turbulence, such
observations are relatively expensive and will be limited to nearby, bright
clusters. In this respect, SB fluctuations are the most economical means to
constrain turbulent motions at large cluster radii across a range of redshifts
and masses.
  To forecast what current and future X-ray and SZ facilities may achieve in SB
fluctuation studies, I review and synthesize matters of accuracy and precision
with respect to calculating power spectra of SB fluctuations, from which
turbulent properties are derived. Balance concerns of power spectrum accuracy
and precision across a range of spatial scales, I propose the use of three
annuli with: [0,0.4] $R_{500}$, [0.4,1] $R_{500}$, and [1,1.5] $R_{500}$.
Adopting these three regions, I calculate the uncertainty in the hydrostatic
mass bias, $\sigma_{b_{\mathcal{M}}}$, can be achieved for various instruments
in several scenarios. I find that $\textit{Lynx}$ and AtLAST are competitive in
their constraints at $R_{500}$, while AtLAST should perform better when
constraining $\sigma_{b_{\mathcal{M}}}$ at $R_{200}$.
