crt1d.solvers.common
====================

.. py:module:: crt1d.solvers.common

.. autoapi-nested-parse::

   Common functions used by canopy RT solvers.



Functions
---------

.. autoapisummary::

   crt1d.solvers.common.K_df_fn
   crt1d.solvers.common.tau_b_fn
   crt1d.solvers.common.tau_df_fn


Module Contents
---------------

.. py:function:: K_df_fn(K_b_fn, lai_tot, **kwargs)

   :math:`K_d` from :math:`K_b(\psi)` and total LAI, using :func:`tau_df_fn`.
   `**kwargs` passed on to :func:`tau_df_fn`.


.. py:function:: tau_b_fn(K_b_fn, psi, lai)

   Transmittance of direct beam through foliage layers(s) with LAI `lai`.

   We need to be able to integrate over different zenith angles (to calulate :math:`\tau_d`),
   so we supply `K_b_fn` instead of ``K_b`` (:math:`K_b`) itself.

   :param K_b_fn: := ``G_fn(psi)/cos(psi)`` where ``G_fn`` computes :math:`G`
                  for the chosen leaf angle distribution function based on :math:`\psi`.
   :type K_b_fn: :class:`function`
   :param psi: Solar zenith angle (radians).
   :type psi: :class:`float` or :term:`array_like`
   :param lai: LAI.
   :type lai: :class:`float` or :term:`array_like`


.. py:function:: tau_df_fn(K_b_fn, lai, *, method='quad')

   Transmittance of diffuse light through foliage layer(s) with LAI `lai`.

   Weighted hemispherical integral of direct beam transmissivity :math:`\tau_b`.
   Isotropy assumption implicit.
   Note that it does not depend on :math:`\psi`.

   :param lai: LAI, one or multiple values.
   :type lai: :class:`float` or :term:`array_like`
   :param method:
   :type method: ``{'quad', '9sky'}``

   .. rubric:: References

   * Campbell & Norman eq. 15.5 :cite:`campbell_introduction_2012`