| Description: | Skyrad normal incident shortwave irradiance (NIP) started reporting impossible values for
direct normal irradiance starting 16 November approx 2100GMT corresponding to a rain
event at the same time.
The NIP was replaced fixing the problem.
Direct normal data are not recoverable. However, the NIP data can be calculated from the
global hemsipherical shortwave and global hemispherical diffuse datastreams by using the
following relationship:
Global Horizontal = Direct Normal x cos(Z) + Diffuse Horizontal
where Z is the zenith angle. |