Introduction
One of the most common causes of fatal helicopter accidents is Controlled Flight Into Terrain (CFIT) at night. (FlightWeb). The major contributor to such accidents is the pilot's level of situational awareness, or rather not being able to see where they are going, or what might be in the way of unobstructed flight. As helicopters are routinely used in low-altitude missions they are frequently required to fly in close proximity to trees, power lines, telephone poles, etc. As such, it is vitally important for the pilot to be able to see and avoid these hazards to navigation. During daylight hours, these hazards pose a minimal risk to flight. However, as the sun sets and the amount of visible light wanes, these same hazards become life threatening.
The reliance on night vision technology has become invaluable in assisting aviators in flying at night. By magnifying the ambient light, Night Vision Goggles (NVG's) and devices reduce the problems associated with unaided vision in the dark.
The Human Eye and Night Vision Goggles
Vision is a physical sense that uses light to provide information to the brain in order to make conclusions about the surroundings. The human eye is an intricate organ that works best when there is an adequate supply of light. Our eyes have been often compared to cameras in that a camera filters light through the lens, controls the intensity with an aperture and focuses the image onto a film. Light coming into an eye is filtered through the cornea, the iris regulates how much light comes through, and then it is focused by the lens onto the retina.
During the day, we are able to detect color, depth perception, distance and visual acuity. At night, all of those senses are greatly diminished. Visual clarity can be reduced to 20/200 or greater at night. The sensitivity of the retina (where images are focused) is greatly hindered when the light levels drop.
On a clear night (with a full moon and no clouds), the unaided eye can make out details of the surrounding terrain from approximately 100 feet in the air. With NVG's, everything on the ground can be clearly seen from an altitude of 1,500 feet above ground, and up.
In using the same camera analogy in describing the eyes, we can use that of a video camera to describe how Night Vision Goggles (NVG's) operate.
Peripheral vision is used amongst every species ranging from a deep-sea marine animal to a bird flying hundreds of feet above the ground. However, each species’ vision differs to some degree and also differentiates within the species itself. This can be due to various types of eye conditions.
This shows that before helicopter rescues weren’t that common, but, now they're 4-5 of them in the sky daily. This has become a major issue because, the weather near the mountains is very unpredictable and it may cause a pilot to lose control. Plus, because there are so many helicopters rescuing climbers everyday, there may not be an left for a real emergency, like an
The retina contains rods and cones which detect the intensity and frequency of incoming light and, in turn, send nerve impulses to the brain.
First, people are given a false sense of security. In a radio interview with Robert Siegel and Nick Heil, Heil says, “If you talk to professional or expert climbers, I think they’re quick to sort of dismiss the fact that they might be influenced by the safety net of a helicopter being available for them.”
Laila confirms that her friends have ordered pizza using her visual system. Through the sensation of light, sensory information is processed and Laila is then able to see the pizza. The pupil absorbs light, by allowing light to enter the eye, and light will then be transferred to the lens. The lens is responsible for refracting light and focusing the light inside of the eye, also known as the retina. The second cranial nerve, or optic nerve, is responsible for carrying the visual signal from the eye to the optic chiasm. The optic nerve, or second cranial nerve, is located in the back of the eye. This cranial nerve transfers visual information to visual centers in the brain through many electric impulses. The optic chiasm has temporal fibers that travel ipsilaterally as nasal fibers transmit information contralaterally, to the opposite side of the associated visual field. The visual cortex can then process sensory information from the opposite eye. Laila’s blind spot is where the optic nerve begins and there are no rod or cone cells in the optic nerve. The brain has to try to compensate for the lack of photosensitive
Now for our eyes we use them for vision, their like our own personal camera’s,
Visual system of the body. The visual system of body is mainly responsible for determining the orientation of a person. Eyes are responsible for giving 90% of information related to orientation. The contradictory messages by other parts of the body are overruled by those of the visual system because visual system is the most trusted sense of a human being (Jacobson, 2010). Although a pilot is flying an airplane in Visual Meteorological Condition (VMC), the visual senses help him or her to keep the airplane oriented to earth. Due to spatial disorientation, the visual systems could become compromised, which could lead to mistakes in the vision system (Wynbrandt,
One sub-system under the sensory system is the visual system; the main sense organs of this are the eyes. The eye is the sensory organ that allows us to detect light from external stimuli. When a light ray is detected, the eye converts these rays into electrical signals that can be sent to the brain in order to process the information and giv...
Who, what and where Vision and Sight are typically used?; In a sentence as the subject or object of a verb or as an object of a preposition. Nevertheless; How and when to use vision and sight is with imagination; a manifestation, something immaterial/ becoming aware of, something worth seeing, a perception. The last question or concern to address is why. Why- Vision and sight; And the answer would simply be because Vision and sight are a sense that without you would not be able to see where you are going, where you are at or what is around you without sight. Without vision you can not prepare, be aware or observe; That which you may not be able to hear, smell, touch, taste. And preparing for one's future, success and dreams as an individual and as well as a whole. Seeing where we are going, where we are at and what is around us, is to be prepared and aware. Through observation our immediate perception is our reality, our future perceptions will be our future reality
Visual perception plays a big part on how we perceive life. If we didn't have perception I don't know where we would be now.
There are many physical and obvious differences between day and night, however there are many subtle differences in human behavior in the day as compared to in the night. People’s behavior differs during the day and night primarily because of fear, lack of scrutiny and judgment, and liberation from obligations.
How would pilots ever get around so easily without the help of navigation aides? Navigational aides have been around for almost as long as aircraft have been flying in the skies above us. The first navigation system was composted of just a high intensity-flashing beacon. These beacons were placed on the flight routes that were popularly flown in the mid 1920’s. With more time more of these technologies that help us navigate the world will be even simpler than today. This paper will explain how some navigational aides work and how some of them came into existence.
Battlefield Augmented Reality System also known as BARS which was developed by Julier et al., provided the soldiers at the battle field with a clear view of the situational awareness. This system was built in so has to help with the various difficulties that the soldiers face on-site such as the lack of visibility, ineffective communications, friend or foe identification and so on (Julier et al., 2000).
The Eye is the organ of sight. Eyes enable people to perform daily tasks and to learn about the world that surrounds them. Sight, or vision, is a rapidly occurring process that involves continuous interaction between the eye, the nervous system, and the brain. When someone looks at an object, what he/she is really seeing is the light that the object reflects, or gives off.