{
  "id": 237013,
  "title": "What I have found so far.",
  "url": "/competitions/indoor-location-navigation/discussion/237013",
  "author_name": "hklee",
  "post_date": "2021-05-06T17:26:31.070000",
  "votes": 16,
  "comment_count": 0,
  "views": 0,
  "content": "<ol>\n<li><p>magnetic sensor reading x, y is the compass direction from carrier's moving direction plus device's orientation.</p></li>\n<li><p>from the rotation and gyroscopic data, the device has little or no extra degree of freedom from the carrier. </p></li>\n<li><p>the values of magnetic sensor z over a floor of a site are consistent which may help location accuracy.</p></li>\n<li><p>accelerometer readings x, y with compass reading will reveal carriers direction.</p></li>\n<li><p>a carrier's accelerations are proportional to his/her device's accelerometer z after band pass filter and hilbert transformation.</p></li>\n<li><p>there are a few prominent devices(wifi+beacon) visible at most of time along the path of a carrier, which I mean that you can see a sharp crest in time vs rssi plot.</p></li>\n<li><p>wifi signals have many isolated local maximas resulting from beam reflections and refractions.</p></li>\n<li><p>beacon signals have not so many local maximas because their signal strengths are weak.</p></li>\n<li><p>some wifi (and beacon) signal are highly directional which manifest themselves when a carrier transverses some aisles.</p></li>\n</ol>",
  "messages": [
    {
      "id": 1295763,
      "postDate": "2021-05-06T17:26:31.070Z",
      "content": "<ol>\n<li><p>magnetic sensor reading x, y is the compass direction from carrier's moving direction plus device's orientation.</p></li>\n<li><p>from the rotation and gyroscopic data, the device has little or no extra degree of freedom from the carrier. </p></li>\n<li><p>the values of magnetic sensor z over a floor of a site are consistent which may help location accuracy.</p></li>\n<li><p>accelerometer readings x, y with compass reading will reveal carriers direction.</p></li>\n<li><p>a carrier's accelerations are proportional to his/her device's accelerometer z after band pass filter and hilbert transformation.</p></li>\n<li><p>there are a few prominent devices(wifi+beacon) visible at most of time along the path of a carrier, which I mean that you can see a sharp crest in time vs rssi plot.</p></li>\n<li><p>wifi signals have many isolated local maximas resulting from beam reflections and refractions.</p></li>\n<li><p>beacon signals have not so many local maximas because their signal strengths are weak.</p></li>\n<li><p>some wifi (and beacon) signal are highly directional which manifest themselves when a carrier transverses some aisles.</p></li>\n</ol>",
      "rawMarkdown": "1. magnetic sensor reading x, y is the compass direction from carrier's moving direction plus device's orientation.\n\n2. from the rotation and gyroscopic data, the device has little or no extra degree of freedom from the carrier. \n\n3. the values of magnetic sensor z over a floor of a site are consistent which may help location accuracy.\n\n4. accelerometer readings x, y with compass reading will reveal carriers direction.\n\n5. a carrier's accelerations are proportional to his/her device's accelerometer z after band pass filter and hilbert transformation.\n\n6. there are a few prominent devices(wifi+beacon) visible at most of time along the path of a carrier, which I mean that you can see a sharp crest in time vs rssi plot.\n\n7. wifi signals have many isolated local maximas resulting from beam reflections and refractions.\n\n8. beacon signals have not so many local maximas because their signal strengths are weak.\n\n9. some wifi (and beacon) signal are highly directional which manifest themselves when a carrier transverses some aisles.\n",
      "votes": 16
    }
  ],
  "comments": [],
  "raw_markdown_by_id": {
    "1295763": "1. magnetic sensor reading x, y is the compass direction from carrier's moving direction plus device's orientation.\n\n2. from the rotation and gyroscopic data, the device has little or no extra degree of freedom from the carrier. \n\n3. the values of magnetic sensor z over a floor of a site are consistent which may help location accuracy.\n\n4. accelerometer readings x, y with compass reading will reveal carriers direction.\n\n5. a carrier's accelerations are proportional to his/her device's accelerometer z after band pass filter and hilbert transformation.\n\n6. there are a few prominent devices(wifi+beacon) visible at most of time along the path of a carrier, which I mean that you can see a sharp crest in time vs rssi plot.\n\n7. wifi signals have many isolated local maximas resulting from beam reflections and refractions.\n\n8. beacon signals have not so many local maximas because their signal strengths are weak.\n\n9. some wifi (and beacon) signal are highly directional which manifest themselves when a carrier transverses some aisles.\n"
  }
}