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thousand or more elements. While there is no rigid dis-
tinction in names between the two extremes, the simpler
packages tend to be referred to as navigation lines while
the more comprehensive are usually described as map-
ping facilities. The facility will frequently be used in
association with automatic ground-stabilization (see
Section 5.3).
5.5 The potential point of collision
(PPC)
The potential point of collision (PPC) is that point
toward which the observing ship should steer at her
present speed (assuming that the target does not man-
oeuvre) in order for a collision to occur.
Some designers have recognized tha ...