Night Vision: How The Heck Does It Work?
Night vision devices need some sort of light source in order to operate. The equipment makes use of small amounts of natural lighting, such as moonlight and starlight. That minuscule amount of light is utilized by converting the light’s energy (photons) into electrical energy, or electrons.
The electrons pass through a small disc inside the night vision device that contains millions of individual channels. As the light makes it’s way through the channels thousands of new electrons are released (multiplied). This new, larger amount of electrons then bounce off a phosphor screen (the greenish glow associated with night vision) that instantly converts the electrons back to photons. This conversion of amplified electrical energy back into light energy (remember, the energy has been greatly amplified at this point) allows the user to see “in the dark.”
Night vision binoculars vary in price. The device above comes in just under $8,000.
Beacons, such as the Phoenix Jr. (above) are used to help prevent friendly-fire accidents. The tiny flashing infrared light can only be seen using night vision (see top image).
A GPS equipped Phoenix Intruder Tripwire Beacon is placed along a pathway traveled by a potential suspect, or other target (military use). The beacon emits a signal that’s both visible and traceable (GPS). For military use mortars may be sent to the beacon’s location, eliminating the target. Police surveillance and apprehension teams would track, locate, and engage their suspect. Then they’d take him into custody.
FYI:
- Night vision does not show normal depth perception.
- Objects with dull surfaces that appear light during the day show up dark at night when viewing with night vision. And, objects that appear dark during the day, but have shiny surfaces, will appear lighter at night when seen with night vision.
- Bright ambient light reduces the images seen through night vision devices. Therefore, reflective light, such as light that’s amplified by rain, fog, mist, etc. hinders the performance of night vision devices.
Posted in Police Tools and Equipment
November 5th, 2009 8:47 am
That minuscule amount of light is utilized by converting the light’s energy (protons) into electrical energy, or electrons.
I’m in edit mode this morning, Lee. You meant to type PHOTONS, not PROTONS, I’m sure.
Thanks for all the info, though! Great post. We have some night vision goggles somewhere (hubby love toys–or was it our son-in-law?) Anyway, I’ve tried them in our backyard, and it’s way cool.
November 5th, 2009 9:09 am
You are exactly right, Terry, and I’ve made the corrections. Thanks.
I’ve got to stop writing these in the wee hours of the morning. 3am for this one.
November 5th, 2009 11:32 am
Lee,
I cannot recall the number of times when hidden up in some dark place doing observations waiting for a villian(s) to arrive and eye strain setting in. Not readily available to the average Cop. We used to improvise and would end up using our own Video Cameras on Night Shot as the next best thing.
Paul
November 5th, 2009 2:04 pm
I learn so much from this site! Did you ever get a hold of Clay Aiken? Wouldn’t need night vision to see that guy in the dark!
Michele
SouthernCityMysteries
November 6th, 2009 3:39 pm
Lee, I really enjoy each of your stories and all the information. It was sad to read about the police officers’ deaths.
But the night goggles sound cool. Much better machinery than this x-ray kind of camera that is taking photos of people and showing them on U tube!!! Yup, right down to skin and underwear. Way too creepy.
Thanks a lot, Lee!
Joann
November 6th, 2009 3:48 pm
Hi Joann. Thanks for the comments. I agree, the x-ray stuff is getting way too personal, but it beats having to strip search someone. Believe me, I’ve seen enough…well, let’s just end it there. I’ve seen enough.