solarpy.quality.diffuse_fraction_flag

solarpy.quality.diffuse_fraction_flag#

solarpy.quality.diffuse_fraction_flag(ghi, dhi, solar_zenith, *, check='both', outside_domain_flag=False, nan_flag=False)#

Flag measurements where the diffuse fraction exceeds physically plausible limits.

The diffuse fraction K = DHI / GHI is tested against solar-zenith-dependent upper limits when GHI exceeds 50 W/m². The limits are:

  • K must be < 1.05 for solar zenith < 75°

  • K must be < 1.10 for 75° ≤ solar zenith < 93°

  • not tested for GHI ≤ 50 W/m² or solar zenith ≥ 93°

The comparison test is part of the BSRN QC tests [1], [2].

Parameters:

  • ghi (array-like of float) – Global horizontal irradiance [W/m²].

  • dhi (array-like of float) – Diffuse horizontal irradiance [W/m²].

  • solar_zenith (array-like of float) – Solar zenith angle [degrees].

  • check ({'high-zenith', 'low-zenith', 'both'}, optional) – Which solar zenith angle domain to check. Default is 'both'.

  • outside_domain_flag (bool, optional) – Value to assign to the flag when conditions are outside the valid test boundary. Can be either True or False. Default is False, which does not flag untested values as suspicious.

  • nan_flag (bool, optional) – If True, flag values where ghi or dhi is NaN. Default is False, which does not flag NaN values as suspicious.

Returns:

flag – Boolean array. True indicates the value failed the test, False indicates it passed or was outside the test domain.

Return type:

same type as ghi

See also

bsrn_limits_flag

References

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