Hi,
I wonder if we can locate stolen devices.
2 Air quality devices have disappeared from our meeting rooms and 1 device is still active as I can see in my console.
Does 3 points measurements with gateways (or another technique) give us the possibility to trace stolen devices?
imho it’s very hard or nearly impossible with the means we have to locate a LoRaWAN-Transmitter by triangulation. The time on air is very short and additionally you have to be sure that the transmission is coming from the node you are searching for.
But maybe the node is seen by other gateways too, then you could make an estimation where it might be.
thank you for the reply,
Indeed, as I have read in previous discussions, it was difficult at the time to determine a position through triangulation. We are now a few years further and I thought it might be possible now, or with further technology.
I have now applied the possibility to use gateways that have picked up the signal and I can more or less determine where this device is located
I need to investigate this further …
you could see on the console where he connect’s (gateway) maybee contact with the owner off the gateway. And look further in that area.
Yes I have now discovered a little more. My first action was indeed to consult the console and I have found that 2 gateways are receiving packets from this missing device
These 2 gateways are located on our campus: gw1 at a height of 50m and gw2 at a height of 70m.
The RSSI values are around -110dB (gw1) and -100dBm (gw2)
Within 500m of gw1 there are 3 other indoor gateways. I still have to map out exactly where they are.
Within 600m of gw1 there are 4 other indoor gws.
However, none of these gateways receive signal from the device.
So I strongly suspect that this missing device is still present on campus …
If the node sends you an air pressure value, you can calculate the altitude of the node.
That’s interesting, the device has a barometric pressure sensor onboard. I have no idea how to calculate that. Fortunately I found an online converter and entered some values, but I get a strange result.
I found The value Pressure at Sea Level for my city on a online weathermap
Temperature and Air Pressure at Altitude are received values from the device
10154 looks like a bit of an obvious typo…unless at the bottom of a deep ocean trench!
Indeed a bit too rushed. Below the values those most recent values:
“airTemp”: 19.80354009308003,
“barometricPress”: 101868, ← according to the manual in hPa?
14.6 m could be a possible, but is the value in hpa or PA?
One Hectopascal (100 Pa) equals 30ft (abt. 8m) in a standard atmosphere. You must use the pressure at sea-level (QNH) from a station nearby.
Or measure the air pressure on the floor and multiply the difference to the pressure indicated by your node by 8. At 15C this gives you the difference of the altitude in m.
Which city would that be? Is it next to the sea?
Rather than rely on theoretical calculations, gleaned from on-line predictions, is it not possible to measure the real difference in air pressure in the specific area at a specific time, using for example a BMX280 ?
The code to do so is trivial.
Thank you al.
This morning I received a phone call from housing management. An employee has removed it for maintenance work and has not replaced it. 
My calculations (Altitude - 14.6m) was not correct cause they where stored in a maintenance room at the first floor.
@wolfp I have my devices back so test this soon 
@descartes Yes, the Netherlands, Eindhoven
Mostly below sea level then, so that makes sense 
Loved going to the science museum in the flying saucer when I was a kid - shame it’s been repurposed.
Yes super building, nowadays equipped with beautiful lighting.
Have fun while measuring your altitude with a barometer like we pilots do.
I have been 2 times at the Evoulon (?) when I was young. imho it was made by Phillips.
Hi @IoT_Marco no problem we do this on a quite often for sensors that are being stolen.
So if this will happen in the future let is know we are also based in The Netherlands