{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Calculating Weighting Functions\n",
    "\n",
    "In this example we calculate weighting functions for ozone using SASKTRAN-Disco. Refer to SASKTRAN-Disco's documentation page for more documentation."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%matplotlib inline\n",
    "\n",
    "import numpy as np\n",
    "import sasktran as sk\n",
    "import sasktran.disco.interface as do\n",
    "import matplotlib.pyplot as plt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Setup the sk.Geometry\n",
    "geometry = sk.NadirGeometry()\n",
    "\n",
    "tempo = sk.Geodetic()\n",
    "tempo.from_lat_lon_alt(0, -100, 35786000)\n",
    "\n",
    "geometry.from_lat_lon(lats=52.131638, lons=-106.633873, elevations=0,\n",
    "    mjd=57906.843, observer=tempo\n",
    ")\n",
    "\n",
    "# Setup the sk.Atmosphere\n",
    "atmosphere = sk.Atmosphere()\n",
    "atmosphere['rayleigh'] = sk.Species(sk.Rayleigh(), sk.MSIS90())\n",
    "atmosphere['o3'] = sk.Species(sk.O3OSIRISRes(), sk.Labow())\n",
    "atmosphere['no2'] = sk.Species(sk.NO2OSIRISRes(), sk.Pratmo())\n",
    "atmosphere.atmospheric_state = sk.MSIS90()\n",
    "atmosphere.brdf = sk.Kokhanovsky()\n",
    "\n",
    "# Construct the engine\n",
    "engine = do.EngineDO(geometry=geometry, atmosphere=atmosphere, wavelengths=[330])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Configure the weighting function calculation\n",
    "atmosphere.wf_species = 'o3'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "scrolled": true
   },
   "outputs": [],
   "source": [
    "rad = engine.calculate_radiance()\n",
    "\n",
    "# Plot weighting function\n",
    "plt.figure()\n",
    "rad['wf_o3'].isel(wavelength=0).plot(y='altitude')\n",
    "plt.ylabel('Altitude [m]')\n",
    "plt.xlabel('dI/dn')\n",
    "plt.show()"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.8.13"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}