Saturday, June 1, 2019

The Human Eye in Space :: essays research papers

Human visual hardware is a result of a billion coursesof evolution within the earths automatic teller machine wherelight is scattered by molecules of air, moisture,particular matter etc. However as we ascend intoour atmosphere with decrease density, lightdistribution is changed resulting in our visualhardware receiving visual data in different format.Some Aspects to Consider 1. visual acuity is the tip to which the details and contours ofobjects are perceived. Visual acuity is usuallydefined in terms of minimum separable.Largevariety of factors influence this complexphenomenon which includes Optical factors-state of the propose forming mechanisms of the eye. Retinal factors such as the state of the cones. Stimulus factors such as illumination, brightness ofthe stimulus, contrast between the stimulus andbackground, length of time exposed to thestimulus. * tokenish separable shortest distanceby which deuce lines can be separated and still beperceived as two lines. "During t he day, the earthhas a preponderantly bluish cast..... I could detectindividual houses and streets in the low humidityand cloudless areas such as the Himalayamountain area.... I saw a steam clean locomotive by chew the fating the smoke first..... I also saw the wake of aboat on a large river in the Burma-India area...and a bright orange light from the British oilrefinery to the south of the city (Perth,Australia.)"The above observation was made by GordonCooper in Faith 7 1963 and which generatedmuch skepticism in the light of the thesis byMuckler and Narvan "Visual Surveillance andReconnaissance from space vehicles" in whichthey determined that a visual incline of ten minuteswas the operational minimum, and that theminimum resolvable object length M.R.O.L at analtitude of 113 miles would be 1730 ft. Thislimitation of acuity was revised the next year to 0.5seconds of arc for an extended contrasting lineand 15 seconds of arc for minimum separation oftwo points sharply co ntrasting with thebackground. Orbiting at 237 miles in the skylab itwas possible to see the entire east coast Canadato Florida Keys and resolve details of a 500 feetlong bridge based on inference. Of Interest is thefact that even though the mechanical eye camerasystems can resolve objects greater than fiftytimes better than the human eye, without thehuman ability to infer, interpretation of the data ismeaningless. Conclusion Visual acuity in spaceexceeds that of earth norm when objects withlinear extension such as roads, airfields, wake ofships etc. 2. Stereoscopic vision the perception oftwo images as one by means of fusing theimpressions on both retinas. In space one has todeal with a poverty of reference points.

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