Night Vision Goggles (NVG discussions merged)
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Night Vision Goggles certified in UK police helicopter
Ananova News report
"Goggles allow chopper cops to see in the dark
Night vision goggles that allow pilots to see in the dark are being pioneered on a police helicopter.
The Devon and Cornwall force helicopter is the first aircraft to be certified by the Civilian Aviation Authority for the pilot and observer to use the goggles full-time for operational use.
Now other UK police forces are monitoring the use of the £15,000 goggles by the south-west force aboard its German-made £2.6 million Eurocopter - the only one in the country.
The force paid £100,000 to have the cockpit of their helicopter, one of the most advanced outside the armed forces, certified to use the goggles.
The goggles, which are mounted on the helmet of the pilot and observer, enable them to see in complete darkness and pick out landmarks and other landscape features.
They improve the crew's ability to navigate safely and to search for offenders and missing people more effectively, says force air support unit manager Captain Ian Payne.
"The goggles make night flying much easier and much safer," said Captain Payne.
The goggles will be used to complement the helicopter thermal imaging camera, which can also track offenders in low light or at night.
The force helicopter unit is also the only one in UK with pilots qualified to navigate by instruments alone.
Night vision goggles that allow pilots to see in the dark are being pioneered on a police helicopter.
The Devon and Cornwall force helicopter is the first aircraft to be certified by the Civilian Aviation Authority for the pilot and observer to use the goggles full-time for operational use.
Now other UK police forces are monitoring the use of the £15,000 goggles by the south-west force aboard its German-made £2.6 million Eurocopter - the only one in the country.
The force paid £100,000 to have the cockpit of their helicopter, one of the most advanced outside the armed forces, certified to use the goggles.
The goggles, which are mounted on the helmet of the pilot and observer, enable them to see in complete darkness and pick out landmarks and other landscape features.
They improve the crew's ability to navigate safely and to search for offenders and missing people more effectively, says force air support unit manager Captain Ian Payne.
"The goggles make night flying much easier and much safer," said Captain Payne.
The goggles will be used to complement the helicopter thermal imaging camera, which can also track offenders in low light or at night.
The force helicopter unit is also the only one in UK with pilots qualified to navigate by instruments alone.
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Vfr, you definately can't just strap them on and go, You need to do a course. It's like flying around looking through two empty toilet roll tubes looking through frosted green glass. Also despite what people think, they're not used for flying in bad weather. You use them purely so you can see where you're going, so that you can avoid bumping into the limpy bits.
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Most of us know, at least in general terms how the night goggles work. I'd be interested to learn a little more detail if anyone who's used them could spare a moment to explain. A Mil pilot?
The force paid £100,000 to have the cockpit certified to use the goggles. What mods have to be made to the cockpit?
The article also says that the force helicopter unit is also the only one in UK with pilots qualified to navigate by instruments alone. Is that correct?
The force paid £100,000 to have the cockpit certified to use the goggles. What mods have to be made to the cockpit?
The article also says that the force helicopter unit is also the only one in UK with pilots qualified to navigate by instruments alone. Is that correct?
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I'm fixed wing but have touched the perifery of NVGs. Modifications are necessary to cockpit lighting - normal cockpit lighting would blind the pilot, because the NVG is effectively an image intensifier, which amplifies the available light. And it's not just a case of turning the brightness down. All in all it is an expensive mod.
The 2 or 3 public service helio units I have come into contact with (police and ambulance) have been day/night VFR ops only, although the VFR limits have been modified to much lower levels (by special authorisation?)
The 2 or 3 public service helio units I have come into contact with (police and ambulance) have been day/night VFR ops only, although the VFR limits have been modified to much lower levels (by special authorisation?)
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I have about 200 hrs NVG, so here goes:
All the cockpit lights have to be modified to 'NVG-compatible' which effectively makes all the lights blue/green (with one or two exceptions like the warning lights!). This is because the traditional red/orange instrument lighting appears extremely bright to the NVG. This causes two effects - flaring, which is like a halo around the light source which blocks out chunks of the field of view, and 'backing-off', which happens when the goggles try to compensate for the bright light by 'turning down the sensitivity'(sort of) which makes the rest of the picture go very dim. This is also caused by street lights, security lighting, car headlamps, red obstruction lights, camera flashes, the moon etc etc. The effect is worsened if it is very dark outside. While they are generally invaluable pieces of kit, they are likely to be of little use if operating in urban areas.
NVG cannot be used in complete darkness as they are image intensifiers, not IR scopes. There has to be some ambient light for them to work. Even faint starlight is enough. In an area with no cultural lighting, no moon and thick cloud to block out the starlight, they can be almost unworkable.
To expand the bad weather point, they can actually lead you further into danger than flying without them. They will hide the fact that it is getting misty, or that you are in thin cloud until the point where the picture suddenly goes blank and you are quite definitely IMC, which is not nice if it's winter and you have no icing clearance!
Overall, they should enhance the Police's capability, but I would caution against treating them as the new 'wonder weapon' of night ops. The Police should also brace themselves for a spate of compensation claims for back and neck injuries as a result of wearing them.
(It a lot more complicated than that (lots of boffin techno-wizardry) but I tried to keep it simple)
Hope that helps
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PCD
All the cockpit lights have to be modified to 'NVG-compatible' which effectively makes all the lights blue/green (with one or two exceptions like the warning lights!). This is because the traditional red/orange instrument lighting appears extremely bright to the NVG. This causes two effects - flaring, which is like a halo around the light source which blocks out chunks of the field of view, and 'backing-off', which happens when the goggles try to compensate for the bright light by 'turning down the sensitivity'(sort of) which makes the rest of the picture go very dim. This is also caused by street lights, security lighting, car headlamps, red obstruction lights, camera flashes, the moon etc etc. The effect is worsened if it is very dark outside. While they are generally invaluable pieces of kit, they are likely to be of little use if operating in urban areas.
NVG cannot be used in complete darkness as they are image intensifiers, not IR scopes. There has to be some ambient light for them to work. Even faint starlight is enough. In an area with no cultural lighting, no moon and thick cloud to block out the starlight, they can be almost unworkable.
To expand the bad weather point, they can actually lead you further into danger than flying without them. They will hide the fact that it is getting misty, or that you are in thin cloud until the point where the picture suddenly goes blank and you are quite definitely IMC, which is not nice if it's winter and you have no icing clearance!
Overall, they should enhance the Police's capability, but I would caution against treating them as the new 'wonder weapon' of night ops. The Police should also brace themselves for a spate of compensation claims for back and neck injuries as a result of wearing them.
(It a lot more complicated than that (lots of boffin techno-wizardry) but I tried to keep it simple)
Hope that helps
------------------
PCD
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Good summary there Plastic.
Pertinent points to raise would probably be the operational aspects too:
Goggles are by no means a replacement for day vision because they provide a monochrome image (hazy shades of green! isn't that a song title?), markedly reduce your depth perception, and I think most importantly remove a good chunk of your peripheral vision.
With the most common types of goggles around in the military, you only get about 40 degrees of vision (the area in front of your face) rather than the nearly 180 that normal day vision gives you. It means that you have to use other strategies to give yourself a lookout that covers what needs to be looked at.
As one of my goggle instructors succinctly put it, "You have to move your head around like one of those noddy dogs that you find in the backs of cars."
Pertinent points to raise would probably be the operational aspects too:
Goggles are by no means a replacement for day vision because they provide a monochrome image (hazy shades of green! isn't that a song title?), markedly reduce your depth perception, and I think most importantly remove a good chunk of your peripheral vision.
With the most common types of goggles around in the military, you only get about 40 degrees of vision (the area in front of your face) rather than the nearly 180 that normal day vision gives you. It means that you have to use other strategies to give yourself a lookout that covers what needs to be looked at.
As one of my goggle instructors succinctly put it, "You have to move your head around like one of those noddy dogs that you find in the backs of cars."
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Light enters the front of the tube in the form of photons. The number of photons depends on the ambient light levels. The photons strike an input screen in the tube and are converted into electrical energy.
This screen is phot-sensitive and multiplies the number of electrons. These electrons are projected onto a phosphor coated screen which converts the electrons back into light in the form of an image.
As previously stated they do not work in complete darkness. On an overcast, no moon night in the desert, you're lucky if you can see the ground from 50'. However in populated countries such as the UK, the cloud reflects the light from built up areas so visibility is usually very good.
Once you've flown with them, you never want to fly in the dark again.
This screen is phot-sensitive and multiplies the number of electrons. These electrons are projected onto a phosphor coated screen which converts the electrons back into light in the form of an image.
As previously stated they do not work in complete darkness. On an overcast, no moon night in the desert, you're lucky if you can see the ground from 50'. However in populated countries such as the UK, the cloud reflects the light from built up areas so visibility is usually very good.
Once you've flown with them, you never want to fly in the dark again.
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Goggles do need some amount of ambient light to work...and they current models are limited to a 40 degree field of view (though research is being done with 110 degree panoramic NVGs). However, current models are capable of 20/25 visual acuity as opposed to best case 20/200 with unaided night vision.
Cockpit light compatibility is another issue...non-NVG compatible lighting inside the cockpit will gain down goggles so much as to make them unusable. The most predominant compatible lighting is blue/green however I have recently heard of white NVG compatible lighting -- an EMS operation in Asheville, NC recently had their bird outfitted for about $12,000 USD.
And as for weather, NVGs can definitely get you into bad situations -- especially in a "pervasive" precip environment like drizzle, rain, & snow. However, in other areas like mountains, desert, etc. you can see low lying fog or rain shafts and maneuver around them. I've used NVGs to direct a USMC KC-130 aerial refueling tanker that was unaided around a rain shaft to avoid us all going into the clouds. Just my $0.02!
Cockpit light compatibility is another issue...non-NVG compatible lighting inside the cockpit will gain down goggles so much as to make them unusable. The most predominant compatible lighting is blue/green however I have recently heard of white NVG compatible lighting -- an EMS operation in Asheville, NC recently had their bird outfitted for about $12,000 USD.
And as for weather, NVGs can definitely get you into bad situations -- especially in a "pervasive" precip environment like drizzle, rain, & snow. However, in other areas like mountains, desert, etc. you can see low lying fog or rain shafts and maneuver around them. I've used NVGs to direct a USMC KC-130 aerial refueling tanker that was unaided around a rain shaft to avoid us all going into the clouds. Just my $0.02!