satpy.modifiers.geometry module

Modifier classes for corrections based on sun and other angles.

class satpy.modifiers.geometry.EffectiveSolarPathLengthCorrector(correction_limit=88.0, **kwargs)

Bases: SunZenithCorrectorBase

Special sun zenith correction with the method proposed by Li and Shibata.

(2006): https://doi.org/10.1175/JAS3682.1

In addition to adjusting the provided reflectances by the cosine of the solar zenith angle, this modifier forces all reflectances beyond a solar zenith angle of max_sza to 0 to reduce noise in the final data. It also gradually reduces the amount of correction done between correction_limit and max_sza. If max_sza is None then a constant correction is applied to zenith angles beyond correction_limit.

To set max_sza to None in a YAML configuration file use:

effective_solar_pathlength_corrected:
  modifier: !!python/name:satpy.modifiers.EffectiveSolarPathLengthCorrector
  max_sza: !!null
  optional_prerequisites:
  - solar_zenith_angle

Collect custom configuration values.

Parameters:

• correction_limit (float) – Maximum solar zenith angle to apply the correction in degrees. Pixels beyond this limit have a constant correction applied. Default 88.

• max_sza (float) – Maximum solar zenith angle in degrees that is considered valid and correctable. Default 95.0.

_apply_correction(proj, coszen)

class satpy.modifiers.geometry.SunZenithCorrector(correction_limit=88.0, **kwargs)

Bases: SunZenithCorrectorBase

Standard sun zenith correction using 1 / cos(sunz).

In addition to adjusting the provided reflectances by the cosine of the solar zenith angle, this modifier forces all reflectances beyond a solar zenith angle of max_sza to 0. It also gradually reduces the amount of correction done between correction_limit and max_sza. If max_sza is None then a constant correction is applied to zenith angles beyond correction_limit.

To set max_sza to None in a YAML configuration file use:

sunz_corrected:
  modifier: !!python/name:satpy.modifiers.SunZenithCorrector
  max_sza: !!null
  optional_prerequisites:
  - solar_zenith_angle

Collect custom configuration values.

Parameters:

• correction_limit (float) – Maximum solar zenith angle to apply the correction in degrees. Pixels beyond this limit have a constant correction applied. Default 88.

• max_sza (float) – Maximum solar zenith angle in degrees that is considered valid and correctable. Default 95.0.

_apply_correction(proj, coszen)

class satpy.modifiers.geometry.SunZenithCorrectorBase(max_sza=95.0, **kwargs)

Bases: ModifierBase

Base class for sun zenith correction modifiers.

Collect custom configuration values.

Parameters:

max_sza (float) – Maximum solar zenith angle in degrees that is considered valid and correctable. Default 95.0.

_apply_correction(proj, coszen)