Operation Of Weapons Research Articles

Visual Mechanisms and Predictors of Far Field Visual Task Performance

Visual mechanisms involved in target detection, recognition, and tracking were examined. Relationships were analyzed in the context of simulated combat, focusing on the short-range air defense weapon operator. Objectives were to identify visual ability interrelations, predictors of performance, and interactions with cuing, target characteristics, and experience. Good predictors included visual acuity, contrast sensitivity, resting focus, near focal point, and blur interpretation. Many of these abilities interacted with the independent variables, producing differential effects on performance. Visual abilities logically grouped into three principal components: active accommodation predicted target detection and identification; passive accommodation predicted detection and acquisition; and image interpretation predicted acquisition, identification, and tracking. Results supported the three visual subsystems hypothesis, based on neurophysiological evidence of pathways in the brain corresponding to specific visual functions.

Fuselage Pressure Fields caused by the 20-mm, M-61-A1 Rapid Fire Gun

Acoustic pressure fields generated by large-caliber rapid-fire weapons are sufficiently intense to constitute sources of concern to airplane designers. The operation of such weapons could result in greatly increased equipment and structure vibration and danger of hearing damage to flight personnel. Acoustic pressures from both fuselage and wing-mounted M-61-A1 guns have been measured on the fuselage and wing of an A-7 airplane. The measurements covered an area extending several feet fore and aft of the gun muzzles. Both static and flight firings were measured. Recordings of acoustic pressure were analyzed for waveform, instantaneous amplitude distributions, spectra, and spacial distribution. The waveform for a burst of fire is approximately a series of decaying sinusoids at the gunfire repetition rate. Peak-to-rms ratios as high as 5 to 6 are not uncommon. On the fuselage near the gun muzzle, peak pressures can reach 2 to 3 psi (177–181 dB SPL). The possible effect of these high-pressure fields on airplane design and operation is discussed in relation to structure and equipment vibration and personnel safety.

ACCURACY AND SPEED OF TACTUAL READING : AN EXPLORATORY STUDY

The study reported here was an attempt to determine the ability of individuals to read words presented tactually. This information has practical implications for military or other situations where the weapon or machine operator may be required to operate his equipment in the absence of visual cues. Six subjects made a total of 540 identifications of words ranging from two to seven letters in length. The average time of performance ranged approximately linearly from 5-5 sec. for two letters to 24-5 sec. for seven letter words. Practice with 90 words during a one hour session resulted in an overall improvement of 29 per cent in time of response. It was also indicated that repeated practice with the same words would reduce the time of performance even further. It is concluded that the time required to impart this type of information to an operator via the touch sense makes this technique practical for most situations where visual cues The accuracy of responses was 97-2 per cent. This high degree of accuracy ...