INTERCEPT PROCEDURES TEXTBOOK
Target Aspect and Rate of Closure
The smaller the TA and AO, the higher the ROC. With zero degrees TA and zero degrees
AO, and both aircraft traveling at 300 knots the ROC will be 600 knots. The illustration
provided below should help you to visualize this concept.
With varying degrees of target aspect and aspect angle, the ROC will be less than it is for
zero degrees of TA. The aircrew can interpolate the drop in ROC as TA increases from 0 to 90.
At the 90 DTG position, the ROC will be the airspeed of the fighter aircraft.