Beyond the sonic-anemometer-based point-measurement methods for estimating heat and momentum fluxes, areal-averaging methods, such as those used by scintillometers, are used in boundary-layer meteorology. Especially over heterogeneous landscapes, the long path length of these systems provides areal averages up to several kilometers that can be useful for incorporation heat and momentum fluxes into numerical weather prediction models (Chehbouni et al. 2000; Lagouarde et al. 2002; Meijninger et al. 2006; Zeweldi et al. 2010; Kleissl et al. 2008). The scintillometer transmits a beam of electromagnetic radiation to a distant receiver and measures the received signal and its intensity variations. The variations directly correspond to variations in the refractive index of the air, which is related to the structure parameter for the refractive index (C_N^2) of the air, which can then be used to estimate the structure function parameter of temperature (C_T^2) and the sensible heat flux as well as momentum flux.
Scintillometer is generally considered to have a TRL of X.