Thin laser beam wandering and intensity fluctuations method for evapotranspiration measurement

• We performed measurements of atmospheric turbulence with two optical methods on a green field.
• We calculate the heat flux values sensed by the laser beam propagation.
• We deduce the evapotranspiration of the field.
• All the optical measurements are compared to results acquired by an eddy-covariant method.
• We compare evapotranspiration calculated with the two measurements.

We compare in this study two simple optical setups to measure the atmospheric turbulence characterized by the refractive index structure parameter Cn2. The corresponding heat flux values sensed by the laser beam propagation are calculated leading to the plant evapotranspiration. The results are discussed and compared to measurements obtained with a well-known and calibrated eddy-covariant instrument. A fine analysis gives a good insight of the accuracy of the optical devices proposed here to measure the crop evapotranspiration. Additional evapotranspiration values calculated with meteorological sensor data and the use of different models are also compared in parallel.