CODEWITHSUNDEEP
node.jswifitrilateration
Eric
Eric

Reputation: 498

NodeJS Wifi Network Trilateration using Lat, Lon & RSSI

I am trying to build an algorithm for locating a WiFi networks approximate location (Lat/Lon) using latitude, longitude and RSSI.

I built a NodeJS wifi scanner that constantly scans for wifi networks. Each network is tracked by mac address and has a tracking array that contains RSSI, Lat coordinate and Lon coordinate that is captured each time the scanner encounters a network.

Using this information, I want to calculate an approximate Lat/Lon coordinate/location for a particular network using the information contained in the tracking array for each access point.

Is there an existing implementation/algorithm for doing this?

"mac": "so:me:ra:nd:om:ac",
"ssid": "elcasa",
"channel": 5,
"tracking": [
  {
    "rssi": -79, // RSSI of signal when encountered by scanner 
    "lat": "some-lat-coord", // Latitude of network when encountered by scanner using GPS
    "lon": "some-lon-coord"  // Longitude of network when encountered by scanner using GPS
  },
  {
    "rssi": -80,
    "lat": "some-lat-coord",
    "lon": "some-lon-coord"
  },
  {
    "rssi": -76,
    "lat": "some-lat-coord",
    "lon": "some-lon-coord"
  },
  {
    "rssi": -78,
    "lat": "some-lat-coord",
    "lon": "some-lon-coord"
  },
  {
    "rssi": -75,
    "lat": "some-lat-coord",
    "lon": "some-lon-coord"
  },
  {
    "rssi": -77,
    "lat": "some-lat-coord",
    "lon": "some-lon-coord"
  },
  {
    "rssi": -74,
    "lat": "some-lat-coord",
    "lon": "some-lon-coord"
  }
]

Upvotes: 1

Views: 520

Answers (1)

Alex Nahas
Alex Nahas

Reputation: 11

An rssi value does not provide enough info to give you a lat and lon.

For large scale cases like cell towers, you need at least two different listening posts to determine a lat and lon and a third if you want to know a depth coordinate.

In most settings where 2.4Ghz and 5Ghz are used, there is a lot of interference and you would need a considerable number of listening posts to determine an approximate coordinate.

Upvotes: 1

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