<p>I've been challenged to think of some really out-of-the-box ways to locate people, and I had one. I'm 90% sure this isn't reasonably possible (probably only in laboratory settings), but I couldn't find a real answer to this question, so now I'm genuinely curious.</p>

<p>It is possible to locate people's location by fluctuations in the Oxygen/Carbon Dioxide levels in the area (from people breathing)?</p>

<p>I realize this is a really general question, and would depend on a ton of factors (size of the area, number of people, proximity of people to an appropriate sensor, etc). I'm really just looking for a general answer, but in case it helps, I'm referring to a general case of detecting people in outdoor settings (it would be part of a sensor suite that is outdoors and just trying to count/locate people in the general area).</p>

<p>Even just a link to a technical paper that explains human impact on immediate area $\sf{O/CO_2}$ levels would be great - I've come up completely empty looking, everything I find just refers to global warming/overall environment/over thousands of years. Nothing for immediate impact, if there is any.</p>

<p>Edit: This was marked as off-topic? Seriously? This is 100% earth science.</p>

CC BY-SA 3.0
2016-04-21T19:23:02.323Z
Indoors, over minutes to hours? Yes. Outdoors? No.
410 gone
CC BY-SA 3.0
2016-04-21T19:25:55.980Z
Common sense agrees, and knows this is likely a silly question, but I'd still like some real details and facts to back it up.  Don't want to make assumptions.
Chris Burrus
CC BY-SA 3.0
2016-04-21T23:06:14.100Z
Right, I know it would have plenty of issues (cars put out some CO2 as well) - but I thought it would at least be worth looking into.
Chris Burrus
CC BY-SA 3.0
2016-04-21T23:37:19.317Z
Mosquitoes do find you this way, so why not...
AtmosphericPrisonEscape
CC BY-SA 3.0
2016-04-22T00:45:13.047Z
The other thing to contend with is other natural sources of CO2 such as CO2 emitted from rocks or geological vents. You might want to check publicly available material on Area 51 in the US. Many years ago I saw a documentary were the claim was made that in addition to other detection devices, The US military had installed methane detectors as another means to detect would-be human intruders.
Fred
CC BY-SA 3.0
2016-04-22T05:11:32.730Z
How would you distinguish between humans and other animals of similar size/metabolic rate?
jamesqf
CC BY-SA 3.0
2016-04-22T12:09:52.007Z
What are you trying to detect? Global population or rather individuals at a local level? Anyway, also check the [People Sniffer](https://en.wikipedia.org/wiki/People_sniffer) used in the Vietnam War. This is based on Ammonia though.
Christoph
CC BY-SA 3.0
2016-04-22T13:16:29.777Z
For what it's worth, this approach is used for detecting stowaways in containers, or otherwise for detecting (but not localising) people in enclosed environments. See http://www.armstrongmonitoring.com/store/shop/showproduct.cfm?id=4&catid=2&startrow=1&classid=1 for an example product. 
I'm doubtful as to whether it could be usefully applied outdoors, though.
Semidiurnal Simon
CC BY-SA 3.0
2016-04-22T18:48:01.787Z
That's at least a start, thanks! Can anyone find an actual whitepaper or similar about this? I've had no luck.
Chris Burrus
<carbon-cycle><co2><oxygen>
Locate people by Oxygen/Carbon Dioxide levels
Chris Burrus
# Locate people by Oxygen/Carbon Dioxide levels

(Asked by: username_0 on 2016-04-21)

I've been challenged to think of some really out-of-the-box ways to locate people, and I had one. I'm 90% sure this isn't reasonably possible (probably only in laboratory settings), but I couldn't find a real answer to this question, so now I'm genuinely curious.

It is possible to locate people's location by fluctuations in the Oxygen/Carbon Dioxide levels in the area (from people breathing)?

I realize this is a really general question, and would depend on a ton of factors (size of the area, number of people, proximity of people to an appropriate sensor, etc). I'm really just looking for a general answer, but in case it helps, I'm referring to a general case of detecting people in outdoor settings (it would be part of a sensor suite that is outdoors and just trying to count/locate people in the general area).

Even just a link to a technical paper that explains human impact on immediate area $\sf{O/CO\_2}$ levels would be great - I've come up completely empty looking, everything I find just refers to global warming/overall environment/over thousands of years. Nothing for immediate impact, if there is any.

Edit: This was marked as off-topic? Seriously? This is 100% earth science.

**Tags:** carbon-cycle, co2, oxygen

> **Comments:**
> **username_1**: Indoors, over minutes to hours? Yes. Outdoors? No.  
> **username_0**: Common sense agrees, and knows this is likely a silly question, but I'd still like some real details and facts to back it up.  Don't want to make assumptions.  
> **username_0**: Right, I know it would have plenty of issues (cars put out some CO2 as well) - but I thought it would at least be worth looking into.  
> **username_2**: Mosquitoes do find you this way, so why not...  
> **username_3**: The other thing to contend with is other natural sources of CO2 such as CO2 emitted from rocks or geological vents. You might want to check publicly available material on Area 51 in the US. Many years ago I saw a documentary were the claim was made that in addition to other detection devices, The US military had installed methane detectors as another means to detect would-be human intruders.  
> **username_4**: How would you distinguish between humans and other animals of similar size/metabolic rate?  
> **username_5**: What are you trying to detect? Global population or rather individuals at a local level? Anyway, also check the [People Sniffer](https://en.wikipedia.org/wiki/People_sniffer) used in the Vietnam War. This is based on Ammonia though.  
> **username_6**: For what it's worth, this approach is used for detecting stowaways in containers, or otherwise for detecting (but not localising) people in enclosed environments. See http://www.armstrongmonitoring.com/store/shop/showproduct.cfm?id=4&catid=2&startrow=1&classid=1 for an example product.  I'm doubtful as to whether it could be usefully applied outdoors, though.  
> **username_0**: That's at least a start, thanks! Can anyone find an actual whitepaper or similar about this? I've had no luck.  

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## 0 answers

