I have calculated the atmospheric loss by below formula according to ITU R
Loss_Atmosphere_Atten = loss_Gaseous_Atten + sqrt((loss_Rain_Atten + loss_Cloud_Atten)^2 + loss_Scintillation^2) ;
I would like to add the XPD cross polarization discrimination in the calculation of total atmospheric loss but i do not know whether i should just add it or take an average with rain attenuation or if any other formula exists, please let me know!! Thanks...