Commander G. A. Long, Jr.

Peer Reviewed

Abstract: Strangely enough, the steps in average speed are approximately logarithmic as we go from one vehicle to another. Therefore, the time required to make a fix with a given permissible error is also logarithmic but in inverse proportion. Concomitant with increase in speed is the rapid decrease in the time of response of the vehicle to control signals. That is, the faster the vehicle, the quicker it will respond to a control signal. These parameters are plotted in Figure 1. The various areas are bounded by limits of speed and speed of response. Man, for instance, can go from zero to about 18 knots in his speed range. His response time may be anywhere from 10 seconds (0.1 cycles per second) to one-tenth second (10 cycles per second) although many people cannot react faster than one-third second (about 3 cycles). This minimum time of response is indicated on the diagram as the range beyond which we cannot expect manual control to be usable. For military purposes, it is safer to consider one-third second response time as the practical limit. The response frequency of controls for ships, automobiles, aircraft and missiles varies greatly with their type of construction and design characteristics as well as with their type of controls. The important fact to be pointed out is that with high speed autos, aircraft and all missiles, man cannot react fast enough to provide satisfactory control. Therefore, although it may be manually supervised, the control of high speed vehicles must be automatic.
Published in: NAVIGATION, Journal of the Institute of Navigation, Volume 2, Number 8
Pages: 290 - 294
Cite this article: Long, Commander G. A., Jr.,, "MISSILE GUIDANCE", NAVIGATION, Journal of The Institute of Navigation, Vol. 2, No. 8, 1950, pp. 290-294.
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