Types of Vision
Photopic, Mesopic, Scotopic
What vision is used during the day and provide 20/20 acuity?
Photopic (Cones located in the Fovea Centralis use photochemical Iodopsin and 1:1 ratio Cones to neurons)
What vision is used during dusk and dawn and full moonlight conditions?
Mesopic (Most dangerous time to fly) (Cones and Rods located in the parafoveal region)
What vision is used at night and has an acuity of 20/200 at best?
Scotopic (Rods located in the peripheral use photochemical rhodopsin and 10:1 to 10,000:1 ration Rods to neurons)
Day blind spot
Caused by a lack of cones and rods in the optic disk. (Cover and area from 5.5 to 7.5 degrees) Binocular vision compensates for this.
Night blind spot
Caused by a lack of rods in the fovea centralis and lack of cone stimulation in the fovea and parafoveal regions (Covers an area 5-10 degrees) scanning compensate for this.
Geometeric Perspective, Retinal Image Size, Aerial perspective, Motion Parallax
Linear perspective, Apparent foreshortening, Vertical Position in field
Retinal Image Size
Known size of object, increasing/decreasing size, terrestrial association, overlapping contours
Fading of colors and shades, Loss of texture and detail, Position of light source
Rapidly moving objects are judged to be near while slower moving objects are judged to be further away.
Flicker Vertigo, False Horizon, Fascination/Fixation, Crater illusion, relative motion illusion, altered planes of reference, size-distance illusion, height-depth perception, confusion with ground lights, autokinesis, reversible perspective
Dark adaption after a brief exposure to bright light?
3 to 5 minutes to regain 45 minute sensitivity
Prolonged exposure to bright lights?
Dark adaption can take 5 hours. Exposure for 2-5 hours may impair night vision for several days
Afocal assembly consist of?
Germanium lens and elevation gimbal assembly
Germanium crystal allows IR energy in what wavelength?
The Germanium crystal is coated on the inside and outside with ______________?
Thorium Fluoride reduces IR energy received to _________?
7.5 - 12 microns
What does the afocal assemble do?
Relay the FLIR image to the FLIR receiver
What does the FLIR receiver do?
Converts image to 16 analog outputs to the FLIR processor
What does to M-PEU do?
FLIR Processing, Power for M-PTUR M-PECA, Communicates with the WP
What power does the PNVS require?
28 Volts DC, 115 VAC 400 Hz
What is IR crossover?
Time of day when soil, water, and concrete termal rediation are nearly equal. (Last 12-30 minutes varies daily)
Reflectance = amount of IR energy reflected (detectable under FLIR)
Absorptance = ratio of radiant energy absorbed by an object
Transmittance=ratio of stored energy that reaches its farther boundary
What are the self-imposed stressors? (DEATH)
Drug, Alcohol, Exhaustion, Tobacco, Hyperglycemia
Do not self medicate because of? (SOAPC)
Overdose, Allergic reaction, Predictable side effects, Synergistic, Caffeine
What is NOE Coupling?
A viewed object/obstacle that emobodies a distinct cold compontet(cold background thermal rendition, such as sky) as compared to the remainder of the same object/obstacle that has a warm background.
what are the PNVS characteristics that the operator should be aware of?
Frozen video, degraded video, loss of BUS communication, Dead Channel, Flashing channels, could shifting, DRC effect, Halo effect.
What is the "f number" of the PNVS and the TADS?
PNVS = f/1.5
TADS = f/2.3
What are the limitations of the TADS?
Azimuth = +120
Elevation = +30 / -60
What are the limitations of the PNVS?
Azimuth = +120
Elevation = +20 / -45
What is the rate of movement for the TADS?
60 Degress per second
What is the reate of movement for the PNVS?
120 Degrees per second
What is the postions of the TADS in the fixed forward position ?
0 degress azimuth
-4.9 degrees elevation
Which side is the NSA and the DSA located on in regards to the TADS?
NSA = left
DSA = right
The DSA contains the following sub-systems?
Day TV (DTV)
Laser Range Finder and Designator (LRFD)
Laser Spot Tracker (LST)
What are your Monocular Cues?
What are the types of Geometric Perspective?
Vertical Position in the Field
What are the types of Retinal Image?
Known size of objects
Increase/Decreaing object size
What are the types of Aeraial Observation?
Fading of colors or shades
Loss of texture of details
Position of light source
What are the visual illusions?
Confusion with Ground Lights
Alternate Planes of Reference
What are the three types of vision
Using Photopic, where are the cones concentrated?
Using Scotopic, where are the rodes concentrated?
Where is the night blind spot located?
5 to 10 degrees wide in the ceter of the cisual field.
Where is the day blind spot located?
5.5 to 7.5 degrees and is located about 15 degrees from the fovea and orginates where the optic nerve attaches to the retina
What are the three night vision veiwing techniques?
Shapes or Silhouettes
One Ounce of alcohol is equal to ____ ft physiologically.
If an individual smokes 3 cigs in rapid succession or 20 to 40 cigs within a 24hour period, how does it affect their alititude and night vision
decrease vision by 20% and 4,000 ft at sea level.
What function does the M-PTUR reciever perform?
Converts IR images to a digital format
What is the function of the M-PECA?
Amplifies azimuth and elevation commands and sends them to the drive motors to move the turret
What are the four types of BIT?
start up/power up (S-BIT, P-BIT)
Event Driven (E-BIT)
What are the two types of night vision devices availible to crewmembers?
Image intensifiers (12), thermal imaging (FLIR)
What is the purpose of thermal imaging systems?
To provide an IR image of a scene by detecting heat
What is the advantage of thermal imagers over image intensifiers?
No light is required to operate a thermal imager
What atmospheric elements affect the composition or density of the atmosphere, and therefore, affect IR signal transmission?
moisture, dust, haze, smoke, fog
What two factors create most of the parallax effect?
angle and distance of the point
**What causes frozen video?
loss of video link comms
What does loss of bus comms result in?
the affected turrett (TADS/PNVS) will move to fixed forward in 5 seconds
What is scene aliasing?
diagonal lines that appear to be out of focus and move back and forth across horizontally orientend linear objects
How is the M-PNVS turned on?
Automatically if APU is on
Manually when using AGPU
What is FLIR polarity?
shade reversal effect
white hot, black hot
How can a crewmember tell what polarity their FLIR system is in?
Look at the sky
sky dark- white hot
sky light- black hot
How can the crewmember using the M-PNVS bring it out of the stow position?
placing NVS switch into norm or fixed
What four considerations must be met prior to optimizing the FLIR?
scene rich in detail
adjust gain and level individually
Which should be optimized 1st, FLIR or IHADSS?
What is the definition of FLIR optimization?
using a combo of level and gain to bring out the most IR detail
What is the primary objective of FLIR adjustment?
quality image for your flight enviornment
What two things should crewmembers ensure before they optimize the FLIR?
FLIR not cool message gone
What establishes the FOV of the M-PNVS?
How can the crewmember in control of the M-PNVS stow the M-PNVS?
What symbology is always presented on the M-PNVS display?
What does the NORM position provide the PLT?
M-PNVS video that is slaved to the pilots helmet
What does the FXD position provde the pilot?
Fixes the M-PNVS to a 0 degree azimuth and -4.9 degree elevation
Which is the DSA and which is the NSA on the TADS?
What major components are located within each section of the TADS?
DSA- DTV, LST, LRFD
What must crews ensure on preflight ?
that the two window covers and the boresight module cover has been removed
Why is the TADS resolution not as good as the PNVS?
IT'S not designed for flight, it's designed for targeting
When is the TADS not an availible selection as a sensor?
when the mode switch is off or if it's being used as a sight
If the CPG is using the TADS as a sight and it is required for NVS flight, what must the CPG do to gain control of the TADS as a sensor?
mode switch to normal or fixed
If either crewmember selects the TADS from a sight oto a sensor, what image will be displayed?
FLIR- wide FOV
What symbology will be displayed on the HDU when using the TADS as a sensor?
What is the fixed FOV of the TADS when used as a sensor?
30 by 40
what is the slew rate of the TADS?
60 deg a second
What are the two stow positions for the TADS?
PARKED 180 deg looking aft
FXD forward - 0 deg AZ and ELEVATION
Which crewmember can stow the TADS?
How can a crewmember select the opposite sensor?
NVS switch to select sensor
Can the PLT always select the TADS from the CPG?
Can the CPG always select the PNVS from the PLT?
If both crewmmembers are using a sensor, what happens if either crewmember selects the NVS select switch?