{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# MAGxHR_1B (Magnetic field 50Hz)\n",
    "\n",
    "> Abstract: Access to the high rate (50Hz) magnetic data (level 1b product)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%load_ext watermark\n",
    "%watermark -i -v -p viresclient,pandas,xarray,matplotlib"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from viresclient import SwarmRequest\n",
    "import datetime as dt\n",
    "import numpy as np\n",
    "import matplotlib.pyplot as plt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "request = SwarmRequest()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Product information\n",
    "\n",
    "The 50Hz measurements of the magnetic field vector (`B_NEC`) and total intensity (`F`).\n",
    "\n",
    "Documentation:\n",
    "- https://earth.esa.int/web/guest/missions/esa-eo-missions/swarm/data-handbook/level-1b-product-definitions#MAGX_HR_1B_Product\n",
    "\n",
    "Measurements are available through VirES as part of collections with names containing `MAGx_HR`, for each Swarm spacecraft:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "request.available_collections(\"MAG_HR\", details=False)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The measurements can be used together with geomagnetic model evaluations as shall be shown below."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Check what \"MAG_HR\" data variables are available"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "request.available_measurements(\"MAG_HR\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Fetch and load data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "request = SwarmRequest()\n",
    "request.set_collection(\"SW_OPER_MAGA_HR_1B\")\n",
    "request.set_products(\n",
    "   measurements=[\"B_NEC\"],\n",
    ")\n",
    "data = request.get_between(\n",
    "   start_time=\"2015-06-21T12:00:00Z\", \n",
    "   end_time=\"2015-06-21T12:01:00Z\",\n",
    "   asynchronous=False\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "data.sources"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "ds = data.as_xarray()\n",
    "ds"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Visualisation of data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fig, axes = plt.subplots(figsize=(20, 3), ncols=3, sharex=True)\n",
    "for i in range(3):\n",
    "    axes[i].plot(ds[\"Timestamp\"], ds[\"B_NEC\"][:, i])\n",
    "    axes[i].set_ylabel(\"NEC\"[i])\n",
    "    axes[i].set_xlabel(\"Time\")\n",
    "fig.suptitle(\"B_NEC components [nT]\");"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fig, ax = plt.subplots(figsize=(20, 3))\n",
    "dBdt = np.diff(ds[\"B_NEC\"], axis=0) * (1/50)\n",
    "ax.plot(ds[\"Timestamp\"][1:], dBdt[:, 2])\n",
    "ax.set_ylabel(\"nT / s\")\n",
    "ax.set_xlabel(\"Time\")\n",
    "ax.set_title(\"Vertical component (C) first differences\");"
   ]
  }
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