Abstract: Large-aperture scintillometer can be used for regional surface heat flux observations and is also an effective tool for measuring surface heat fluxes at the satellite image scale. For the improvement of satellite product algorithms and observation methods, it is crucial to validate the accuracy of satellite products utilizing surface relative truth of scintillator. To preliminarily solve the problem of satellite product calibration, two scintillometer stations in Hebi, Henan Province, and Ulanqab, Inner Mongolia, China were selected. Based on the theory of near ground similarity and combined with the meteorological information observed, the refractive index structure constant output from the scintillometers was processed. Then the sensible and latent heat fluxes were calculated using an iterative algorithm, and the accuracy of scintillometers was verified taking the measurement results of the eddy correlation meter in Hebi area as reference. Additionally, the latent heat flux data in MOD16A2 remote sensing evapotranspiration products were ground-checked using scintillometer data from the Ulanqab region. The results demonstrate that the scintillometer inversion results have high accuracy, high correlation with the eddy data, and highly match the scale of the elements in satellite images, allowing for the use of these data as ground calibration of satellite products.

Key words: latent heat flux, large aperture scintillometer, eddy covariance system, ground calibration