NSRDB, PVGIS details, home page sketch

Author: tobin-ford

docs/source/PVDeg-Flow.svg

@@ -25,12 +25,14 @@ relative humidity in the outside, front and back encapsulant and backsheet,
 spectral degradation, and solder fatigue. More functions for standards and
 other degradation profiles are in the works.
 
-The source code for pvdeg is hosted on `github
-<https://github.com/NREL/pvdeg>`_.
+The source code for pvdeg is hosted on `github <https://github.com/NREL/pvdeg>`_. Please see the :ref:`installation` page for installation help.
 
 See :ref:`tutorials` to learn how to use and experiment with various functionalities
 
-Please see the :ref:`installation` page for installation help.
+
+.. image::  PVDeg-Flow.svg
+    :alt: PVDeg-Flow diagram.
+
 
 How the Model Works
 ===================
@@ -51,9 +53,17 @@ Citing PVDegradation Tools
 
 If you use this calculator in a published work, please cite:
 
+.. code-block::
+
+   Holsapple, Derek, Ayala Pelaez, Silvana, Kempe, Michael. "PV Degradation Tools", NREL Github 2020, Software Record SWR-20-71.
+
 
 Please also cite the DOI corresponding to the specific version that you used.
-DOIs are listed at Zenodo.org
+DOIs are listed at Zenodo.org. `linked here <https://zenodo.org/records/13760911>`_
+
+.. code-block::
+
+   Martin Springer, Tobin Ford, Matt, MDKempe, Silvana Ovaitt, AidanWesley, joe karas, Mark Campanelli, Derek M Holsapple, and Kevin Anderson. “NREL/PVDegradationTools: 0.4.2.” Zenodo, 2024. doi:10.5281/zenodo.13760911.
 
 
 .. toctree::

docs/source/index.rst

@@ -8,6 +8,7 @@ User Guide
 
    installation
    package_overview
+   meteorological-data
    NSRDB_API_Key
    montecarlo
    geospatial-templates

docs/source/user_guide/index.rst

@@ -0,0 +1,58 @@
+.. _meteorological-data.rst:
+
+Meterological Data
+==================
+
+PVDeg seeks to automate the tedious parts of degredation analysis by providing simple tools to work with weather data. 
+``pvdeg.weather.get`` seeks to unify this functionality into a simple function.
+
+The PVDeg tutorials and examples use two datasets, `NSRDB`_ and `PVGIS`_. These are serially complete data including meteorological data and solar radiation (irradiance) measurements.
+The methodology for these datasets varies but both are gridded geospatial datasets with similar attributes.
+
+NSRDB 
+------
+The NSRDB is produced by NREL and combines multiple datasets but we are most concerned with `Physical Solar Model 3 (PSM3) <https://developer.nrel.gov/docs/solar/nsrdb/psm3-2-2-download/>`_. This data was generated using satellite data from multiple channels to derive cloud 
+and aerosol properties, then fed into a radiative transfer model. Learn more about the NSRDB `here <https://nsrdb.nrel.gov/about/what-is-the-nsrdb#:~:text=The%20PSM%20is%20a%20two-step%20physical%20modeling%20process%2C,%28Xie%20et%20al.%2C%202016%29%2C%20in%20the%20subsequent%20step.>`_. 
+
+The NSRDB is free to use but requires an api-key and email. See :ref:`NSRDB_API_Key` for more information. 
+For our purposes, the api is limited to 1000 requests per day, although you can request a batch download via email with a singificantly higher rate limit (not recommended for PVDeg).
+
+Flowchart showing the dataflow from satellite to solar radiation measurement.
+
+.. image::  meteorological-data-details/data_flow_chart.png
+    :alt: dataflow from satellite to solar radiation measurement, image missing
+
+`<https://nsrdb.nrel.gov/about/what-is-the-nsrdb>`_
+
+NSRDB data are seperated by satellite/model source. Each dataset is shown below, much of the PVDeg project uses the *Americas* data.
+
+.. image::  meteorological-data-details/nsrdb_global_coverage.jpg
+    :alt: NSRDB data sources, image missing
+
+`<https://nsrdb.nrel.gov/about/what-is-the-nsrdb>`_
+
+PVGIS
+------
+`PVGIS`_ is the European counterpart of the `NSRDB`_. The data was sourced similarly. With PVGIS we are most concerned with a `typical meteorological year <https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis/pvgis-tools/pvgis-typical-meteorological-year-tmy-generator_en>`_.
+PVDeg uses utilities built in `pvlib <https://pvlib-python.readthedocs.io/en/stable/index.html>`_ to access the data.
+
+PVGIS is free to use and does NOT require an api-key. It has a rate limit of 30 requests per second and covers a much larger range of longitudes and latitudes.
+
+The PVDeg tutorials and examples use two datasets, `NSRDB`_ and `PVGIS`_. These are serially complete data including meteorological data and solar radiation (irradiance) measurements.
+The methodology for these datasets varies but both are gridded geospatial datasets with similar attributes.
+
+PVGIS data are seperated by satellite/model source. Each satellite source for PVGIS 5.2 is shown below.
+
+.. image::  meteorological-data-details/pvgis-52.png
+    :alt: PVGIS 5.2 satellite sources, image missing
+
+`<https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis/pvgis-releases/pvgis-52_en>`_
+
+Sources for PVGIS 5.3
+
+.. image::  meteorological-data-details/pvgis-53.png
+    :alt: PVGIS 5.3 satellite sources, image missing
+
+`<https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis/pvgis-releases/pvgis-53_en>`_ 
+
+**demonstrations of ``weather.get`` for each type**