The latent heat flux can be converted to evapotranspiration by dividing by the latent heat of vaporization:

ET = LE/(latent heat of vaporization).

There are gap-filling algorithms that can be used for missing data. I would recommend reading the following paper (see Appendix A):

Reichstein, M., Falge, E., Baldocchi, D., Papale, D., Aubinet, M., Berbigier, P., et al. (2005). On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm. Global Change Biology, 11(9), 1424–1439. https://doi.org/10.1111/j.1365-2486.2005.001002.x

There are software packages available for performing gap-filling, for example REddyProc (https://www.bgc-jena.mpg.de/bgi/index.php/Services/REddyProcWebRPackage)

Hi Justine Missik,

Thanks for your help.

Is raw data need correction with bowen-ratio or so on?

Hi Fatma,

I think when you have latent heat flux, you can easily convert it to evapotranspiration by dividing it by the latent heat of vaporization without any other correction. BTW, the reliability of the data is a big challenge.

Hi Mostafa Javadian,

Thanks for your help.

you can use easy flux there are two versions of easyflux available one to process the data within the data-logger and you will get the corrected LE from the easyflux other called easyflux PC same like eddy pro but this one is made by Campbell and Eddypro by Li core, the conditions of having soil heat flux plates and Net radiometer are necessary then at the end you can divide your estimated LE with Lv (Heat of vaporization) to measure your required ET.