Core Functions

class pyrism.core.Kernel(iza, vza, raa, normalize=False, nbar=0.0, angle_unit='DEG', align=True)[source]

Bases: object

The kernel object defines the different models.

Parameters:
  • vza, raa (iza,) – Incidence (iza) and scattering (vza) zenith angle, as well as relative azimuth (raa) angle.
  • normalize (boolean, optional) – Set to ‘True’ to make kernels 0 at nadir view illumination. Since all implemented kernels are normalized the default value is False.
  • nbar (float, optional) – The sun or incidence zenith angle at which the isotropic term is set to if normalize is True. The default value is 0.0.
  • angle_unit ({'DEG', 'RAD'}, optional) –
    • ‘DEG’: All input angles (iza, vza, raa) are in [DEG] (default).
    • ’RAD’: All input angles (iza, vza, raa) are in [RAD].
  • align (boolean, optional) – Expand all input values to the same length (default).
Returns:

  • All returns are attributes!
  • iza (ndarray) – Sun or incidence zenith angle in [RAD].
  • vza (ndarray) – View or scattering zenith angle in [RAD].
  • raa (ndarray) – Relative azimuth angle in [RAD].
  • izaDeg (ndarray) – Sun or incidence zenith angle in [DEG].
  • vzaDeg (ndarray) – View or scattering zenith angle in [DEG].
  • raaDeg (ndarray) – Relative azimuth angle in [DEG].
  • phi (ndarray) – Relative azimuth angle in a range between 0 and 2pi.

Note

Hot spot direction is vza == iza and raa = 0.0

normalization(kernel=None, args=None)[source]
class pyrism.core.Scattering(frequency, particle_size, diel_constant_p, diel_constant_b)[source]

Bases: object

Calculate the extinction coefficients in terms of Rayleigh or Mie scattering from [UL15a] and [UL15b].

Parameters:
  • frequency (int or float) – Frequency (GHz)
  • particle_size (int, float or array) – Particle size a (cm).
  • diel_constant_p (complex) – Dielectric constant of the medium.
  • diel_constant_b (complex) – Dielectric constant of the background.

References

[UL15a]Fawwaz T. Ulaby and David G. Long. Microwave Radar and Radiometric Remote Sensing. Artech House, Norwood, 2015. ISBN 978-0-472-11935-6. URL: http://gbv.eblib.com/patron/FullRecord.aspx?p=4537961.
[UL15b]Fawwaz T. Ulaby and David G. Long. Microwave radar and radiometric remote sensing: remote sensing computer codes. 2015. URL: http://mrs.eecs.umich.edu/microwave_remote_sensing_computer_codes.html.