  Scintillometer measurements of the turbulence inner-scale length $l_o$ and
refractive index structure function $C_n^2$ allow for the retrieval of
large-scale area-averaged turbulent fluxes in the atmospheric surface layer.
This retrieval involves the solution of the non-linear set of equations defined
by the Monin-Obukhov similarity hypothesis. A new method that uses an analytic
solution to the set of equations is presented, which leads to a stable and
efficient numerical method of computation that has the potential of eliminating
computational error. Mathematical expressions are derived that map out the
sensitivity of the turbulent flux measurements to uncertainties in source
measurements such as $l_o$. These sensitivity functions differ from results in
the previous literature; the reasons for the differences are explored.
