.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "gallery/quality/plot_bsrn_limits.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_gallery_quality_plot_bsrn_limits.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_gallery_quality_plot_bsrn_limits.py:


BSRN limits
===========

The BSRN limit checks specify upper and lower limits for solar irradiance measurements,
defining boundaries for GHI, DHI, and DNI as a function of the extraterrestrial irradiance.

.. GENERATED FROM PYTHON SOURCE LINES 10-23

The BSRN limits can be calculated using
:py:func:`solarpy.quality.bsrn_limits`, and the corresponding quality flags
can be calculated using :py:func:`solarpy.quality.bsrn_limits_flag`.

There are two sets of limits for each component: the extremely rare limits (ERL),
which are expected to be exceeded only in very rare cases, and the physically
possible limits (PPL), which are not expected to be exceeded.

In the example below, GHI, DHI, and DNI measurements are plotted against
the extraterrestrial irradiance on a horizontal plane using
:py:func:`solarpy.plotting.plot_bsrn_limits`. The red shaded areas correspond to
the ERL and PPL limits; the width of each band accounts for the variation of
the Sun-Earth distance over the course of a year.

.. GENERATED FROM PYTHON SOURCE LINES 25-30

Load example data
-----------------

The example data is from DTU's station in Lyngby, Denmark north of Copenhagen.
The data is from 2023 and includes measurements of GHI, DHI, and DNI at a 1-minute resolution.

.. GENERATED FROM PYTHON SOURCE LINES 30-51

.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np
    import pvlib
    import solarpy

    data, meta = solarpy.iotools.read_t16(
        "https://raw.githubusercontent.com/AssessingSolar/solarpy/refs/heads/main/data/LYN_2023.csv",  # noqa: E501
        map_variables=True,
    )

    # Calculate solar position
    solar_position = pvlib.solarposition.get_solarposition(
        data.index, latitude=meta["latitude"], longitude=meta["longitude"]
    )

    # Calculate extraterrestrial irradiance on a horizontal plane
    dni_extra = pvlib.irradiance.get_extra_radiation(data.index)
    cos_sza = np.cos(np.deg2rad(solar_position["apparent_zenith"])).clip(lower=0)
    ghi_extra = dni_extra * cos_sza








.. GENERATED FROM PYTHON SOURCE LINES 52-61

Plot BSRN limits for GHI
------------------------

The irradiance data is plotted against the extraterrestrial irradiance
using a scatter heatmap to differentiate between high and low density areas.

The BSRN limits are plotted as red shaded areas. # Measurements falling outside
the red bands are flagged as suspicious by
:py:func:`solarpy.quality.bsrn_limits_flag` and should be inspected further.

.. GENERATED FROM PYTHON SOURCE LINES 61-70

.. code-block:: Python


    fig, axes = solarpy.plotting.plot_bsrn_limits(
        irradiance=data["ghi"],
        component="ghi",
        ghi_extra=ghi_extra,
    )

    fig.tight_layout()




.. image-sg:: /gallery/quality/images/sphx_glr_plot_bsrn_limits_001.png
   :alt: plot bsrn limits
   :srcset: /gallery/quality/images/sphx_glr_plot_bsrn_limits_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 71-73

Plot BSRN limits for all three components
-----------------------------------------

.. GENERATED FROM PYTHON SOURCE LINES 73-85

.. code-block:: Python


    fig, axes = plt.subplots(ncols=3, figsize=(10, 5), sharey=True)

    for ax, component in zip(axes, ["ghi", "dhi", "dni"]):
        solarpy.plotting.plot_bsrn_limits(
            irradiance=data[component],
            component=component,
            ghi_extra=ghi_extra,
            ax=ax,
        )

    fig.tight_layout()



.. image-sg:: /gallery/quality/images/sphx_glr_plot_bsrn_limits_002.png
   :alt: plot bsrn limits
   :srcset: /gallery/quality/images/sphx_glr_plot_bsrn_limits_002.png
   :class: sphx-glr-single-img






.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 5.190 seconds)

**Estimated memory usage:**  311 MB


.. _sphx_glr_download_gallery_quality_plot_bsrn_limits.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_bsrn_limits.ipynb <plot_bsrn_limits.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_bsrn_limits.py <plot_bsrn_limits.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_bsrn_limits.zip <plot_bsrn_limits.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_