Focused heat sensor circuit

[Pax Writer]

Hey experts

I'd like to build a circuit which can detect people within 10-15 metres in a small angle of about 15 degrees (or narrower if possible). It should be fast enough to detect even if people run through the "beam".
The circuit should be relatively compact and will run on battery power (no particular voltage decided yet)
Is such a circuit realistic?
If you have any thoughts to share or links to someplace where someone already invented this little circuit, please feel free to post.
All help will be appreciated.
Thanks

 

[ericgibbs]

Hey experts

I'd like to build a circuit which can detect people within 10-15 metres in a small angle of about 15 degrees (or narrower if possible). It should be fast enough to detect even if people run through the "beam".
The circuit should be relatively compact and will run on battery power (no particular voltage decided yet)
Is such a circuit realistic?
If you have any thoughts to share or links to someplace where someone already invented this little circuit, please feel free to post.
All help will be appreciated.
Thanks

hi,
Such devices are already on the market.

**broken link removed**

If you Google narrow angle PIR sensors you will get lots of information.

 

[Pax Writer]

That was exactly the advice I needed.
The correct buzz word to search for and a link to go with it.
Thanks!