How to generate GPP without dependence on the Ustar?

[Liweinjau]

In my eddy convince data, there is no Ustar data. How can i generate the half-hour GPP by using the half-hour 'Year', 'Doy', 'NEE', 'Rg' and 'Tair'.

[bgctw]

Dear Liweinjau, the Ustar friction velocity is important to detect periods of low turbulence, where the conditions for applying the eddy covariance (EC) method are not met, and give wrong results. UStar is measured by the EC system and used to compute the NEE fluxes, hence it should be available. You need to talk to the technicians operating the EC site and computing half-hourly fluxes how to log and provide Ustar it to you.

If you have EC data which is already uStar-filtered and gap-filled, you could rename NEE to NEE_uStar_f and Tair to Tair_f in your soure data and use the REddyProc package to create REddyProc class with those columns and then invoke the partitioning routines.