captest.filters.backtracking_active

captest.filters.backtracking_active(apparent_zenith, solar_azimuth, axis_tilt, axis_azimuth, gcr, cross_axis_tilt=0)

Return a boolean Series marking single-axis-tracker backtracking.

Direct transcription of pvlib’s tracking.singleaxis backtracking test (Anderson & Mikofski 2020): an interval is backtracking-active when the sun is above the horizon (apparent_zenith <= 90) and row-to-row shade would occur under true-tracking.

Parameters:

  • apparent_zenith (pd.Series) – Apparent solar zenith angle (degrees).

  • solar_azimuth (pd.Series) – Solar azimuth angle (degrees).

  • axis_tilt (float) – Tracker axis tilt (degrees).

  • axis_azimuth (float) – Tracker axis azimuth (degrees).

  • gcr (float) – Ground coverage ratio; must be greater than 0.

  • cross_axis_tilt (float, default 0) – Cross-axis tilt (degrees); must be in the open interval (-90, 90).

Returns:

Boolean Series indexed like apparent_zenith; True where backtracking is geometrically active.

Return type:

pd.Series

Raises:

ValueError – If the geometry is invalid (see _backtracking_geometry_error).