Military Grid Reference System (MGRS)

MGRS.ipynb

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   "cell_type": "markdown",
   "id": "7933de33",
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   "source": [
    "# Download Military Grid Reference System (MGRS) 100km grid lines\n",
    "\n",
    "https://earth-info.nga.mil/index.php?dir=coordsys&action=mgrs-100km-polyline-dloads"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "cc3852a2",
   "metadata": {},
   "outputs": [],
   "source": [
    "import os\n",
    "import requests\n",
    "import pandas as pd"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "863e666c",
   "metadata": {},
   "outputs": [],
   "source": [
    "url = \"https://github.com/opengeos/datasets/releases/download/world/mgrs_grid_zone.csv\"\n",
    "# missing 49X, 50X, 58X\n",
    "# Zone 28 files only contain .shp files without dbf files\n",
    "df = pd.read_csv(url)\n",
    "zones = df[\"GZD\"].to_list()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "73b86227",
   "metadata": {},
   "outputs": [],
   "source": [
    "for index, zone in enumerate(zones):\n",
    "    print(f\"Downloading {index + 1}/{len(zones)}: {zone}\")\n",
    "\n",
    "    # URL for the file\n",
    "    url = f\"https://earth-info.nga.mil/php/download.php?file=MGRS_100kmSQ_ID_{zone}\"\n",
    "    filename = f\"MGRS_100kmSQ_ID_{zone}.zip\"\n",
    "    if os.path.exists(filename):\n",
    "        # print(f\"File {filename} already exists. Skipping download.\")\n",
    "        continue\n",
    "    else:\n",
    "        print(f\"File {filename} does not exist. Downloading...\")\n",
    "    # Custom headers to mimic a browser\n",
    "    headers = {\n",
    "        \"User-Agent\": \"Mozilla/5.0\"\n",
    "    }\n",
    "\n",
    "    # Send the GET request\n",
    "\n",
    "    try:\n",
    "        response = requests.get(url, headers=headers)\n",
    "\n",
    "        # Check if download was successful\n",
    "        if response.status_code == 200 and \"Content-Disposition\" in response.headers:\n",
    "            filename = response.headers[\"Content-Disposition\"].split(\"filename=\")[-1].strip('\"')\n",
    "            with open(filename, \"wb\") as f:\n",
    "                f.write(response.content)\n",
    "            print(f\"Downloaded: {filename}\")\n",
    "        else:\n",
    "            print(f\"Failed to download. Status code: {response.status_code}\")\n",
    "    except Exception as e:\n",
    "        print(f\"An error occurred: {e}\")\n",
    "        continue\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "693e23d7",
   "metadata": {},
   "outputs": [],
   "source": [
    "import leafmap"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "3badb4fe",
   "metadata": {},
   "outputs": [],
   "source": [
    "files = leafmap.find_files(\".\", ext=\".shp\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "15f1b21d",
   "metadata": {},
   "outputs": [],
   "source": [
    "len(files)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "25b008d2",
   "metadata": {},
   "outputs": [],
   "source": [
    "gdf = leafmap.merge_vector(files, crs=\"EPSG:4326\", return_gdf=True)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "59ed1b1f",
   "metadata": {},
   "outputs": [],
   "source": [
    "gdf"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "36c58e90",
   "metadata": {},
   "outputs": [],
   "source": [
    "gdf[[\"100kmSQ_ID\", \"GZD\", \"MGRS\", \"geometry\"]].to_file(\"MGRS_100km.gpkg\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "8f2e44f6",
   "metadata": {},
   "source": [
    "Convert to PMTiles\n",
    "\n",
    "```bash\n",
    "ogr2ogr -skipfailures -f PMTiles -dsco MINZOOM=0 -dsco MAXZOOM=15 MGRS_100km.pmtiles MGRS_100km.parquet\n",
    "```"
   ]
  }
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