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  {
   "cell_type": "markdown",
   "id": "9e33a56f",
   "metadata": {},
   "source": [
    "# Example - 71 - Uranus Arrival, Approach, Entry State"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "48a32d8d",
   "metadata": {},
   "source": [
    "In this example we illustrate the use of AMAT to compute the state at atmospheric entry for two approach trajectories: one prograde and other retrograde."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "919b9aba",
   "metadata": {},
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "from astropy.time import Time\n",
    "import matplotlib.pyplot as plt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "b4db1909",
   "metadata": {},
   "outputs": [],
   "source": [
    "from AMAT.planet import Planet\n",
    "from AMAT.arrival import Arrival\n",
    "from AMAT.approach import Approach\n",
    "from AMAT.vehicle import Vehicle"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "bee9cf57",
   "metadata": {},
   "outputs": [],
   "source": [
    "arrival = Arrival()\n",
    "arrival.set_vinf_vec_from_lambert_arc('JUPITER',\n",
    "                                  'URANUS',\n",
    "                                  Time(\"2035-09-04 00:00:00\", scale='tdb'),\n",
    "                                  Time(\"2039-05-18 00:00:00\", scale='tdb'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "3bf729b4",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Entry altitude, km: 1000.0\n",
      "Entry longitude BI, deg: -80.95\n",
      "Entry latitude BI, deg: 25.22\n",
      "Atm. relative entry speed, km/s: 27.5946\n",
      "Atm. relative heading angle, deg: 132.066\n",
      "Atm. relative EFPA, deg: -11.1875\n"
     ]
    }
   ],
   "source": [
    "# prograde approach\n",
    "approach1 = Approach(\"URANUS\", v_inf_vec_icrf_kms=arrival.v_inf_vec,\n",
    "                            rp=(25559+400)*1e3, psi=3*np.pi/2,\n",
    "                            is_entrySystem=True, h_EI=1000e3)\n",
    "\n",
    "print(\"Entry altitude, km: \"+ str(approach1.h_EI/1e3))\n",
    "print(\"Entry longitude BI, deg: \"+ str(round(approach1.longitude_entry_bi*180/np.pi, 2)))\n",
    "print(\"Entry latitude BI, deg: \"+ str(round(approach1.latitude_entry_bi*180/np.pi, 2)))\n",
    "print(\"Atm. relative entry speed, km/s: \"+str(round(approach1.v_entry_atm_mag/1e3, 4)))\n",
    "print(\"Atm. relative heading angle, deg: \"+str(round(approach1.heading_entry_atm*180/np.pi, 4)))\n",
    "print(\"Atm. relative EFPA, deg: \"+str(round(approach1.gamma_entry_atm*180/np.pi, 4)))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "09f92eab",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Entry altitude, km: 1000.0\n",
      "Entry longitude BI, deg: 50.51\n",
      "Entry latitude BI, deg: 25.22\n",
      "Atm. relative entry speed, km/s: 31.0646\n",
      "Atm. relative heading angle, deg: 41.2577\n",
      "Atm. relative EFPA, deg: -9.9243\n"
     ]
    }
   ],
   "source": [
    "# retrograde approach\n",
    "approach1 = Approach(\"URANUS\", v_inf_vec_icrf_kms=arrival.v_inf_vec,\n",
    "                            rp=(25559+400)*1e3, psi=np.pi/2,\n",
    "                            is_entrySystem=True, h_EI=1000e3)\n",
    "\n",
    "print(\"Entry altitude, km: \"+ str(approach1.h_EI/1e3))\n",
    "print(\"Entry longitude BI, deg: \"+ str(round(approach1.longitude_entry_bi*180/np.pi, 2)))\n",
    "print(\"Entry latitude BI, deg: \"+ str(round(approach1.latitude_entry_bi*180/np.pi, 2)))\n",
    "print(\"Atm. relative entry speed, km/s: \"+str(round(approach1.v_entry_atm_mag/1e3, 4)))\n",
    "print(\"Atm. relative heading angle, deg: \"+str(round(approach1.heading_entry_atm*180/np.pi, 4)))\n",
    "print(\"Atm. relative EFPA, deg: \"+str(round(approach1.gamma_entry_atm*180/np.pi, 4)))"
   ]
  }
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