Human Systems Integration Division @ NASA Ames

Because crews in aerospace vehicles can be exposed to significant vibration, Adelstein, Kaiser, Beutter, McCann, and Anderson (Acta Astronautica, 2012) examined the effect of vibrating observers at 12 Hz on their ability to read numeric symbols on stationary displays and found performance degradation with increasing vibration amplitude. The observer's task was to read a trigram of digits and respond by pressing the right button if the digit sequence was monotonic increasing or pressing the left button if was not. They also showed the efficacy of a display-strobing countermeasure for the reading decrements. We have adapted the model of Watson and Ahumada (J. Vis., 2008) for predicting letter identification in the presence of optical blur to the prediction of the effects of sinusoidal vibration blur on their reading task. The blur kernel was the one dimensional orthogonal projection of a circle. The model can account for the degradation caused by motion blur and the release from degradation resulting from strobing the backlight of the display with varying strobe duty cycles.