1. surveyed pertinent literature regarding the effects of variation in display quality upon measured human operator describing functions in laboratory tracking tasks. Citing six studies (Refs. 11, 13-17, here), it was shown that reduction in display quality of various types resulted in (1) an increase in the effective time delay in the human operator describing function, and (2) an increase in tracking error in the task(s) at hand. Reference 11 demonstrated that the increase in time delay could be attributed to a gain reduction in the propriopceptive feedback used by the human operator, i.e., the delay increase may not be associated with the visual process, per se. However, it was felt that a baseline delay increase associated with the visual process when using degraded displays would be a reasonable modeling assumption. With this in mind, the two operations considered to be essential to a visual cue model were (1) sampling, and (2) noise corruption.
2. 271 2-50-0.0628sec«0.06sec(7)