Radar System Engineering

214 THE EMPLOYMENT OF RADAR DATA [SEC.7.2
supply and maintain the equipment required by mechanization. The
advantage of making this substitution is two-fold: the latter skills can
be applied under favorable conditions, while operator skill is required in
the field on the occasion of each crisis; further, there are usually many
more operators of a given equipment than there are designers, production
engineers, and maintenance men, combined. The total skill required is
thus more economically used under more favorable conditions if mechanization
is employed.
Most problems involving radar are far simpler than that of antiaircraft
fire control. A simple set may be used on a ship, for example, for
navigation and collision avoidance. Under these circumstances, all that
is required is a good PPI display on the bridge, and perhaps an alarm
that gives a signal if a radar target approaches within a mile. Very good
navigation can be performed by comparing the PPI with a chart and
taking the range and bearing of sufficient identifiable points shown on the
radar to determine the location of the ship. The organization required
beyond the radar indicator consists in this case of very little more than
the ship’s navigator.
The problem of creating the most efficient organization for the use of
radar data, in each functional situation involving radar, is a very complicated
one. During the war, it lacked the systematic study that its
importance and its complexity deserved. Since any treat ment of system
design would be incomplete without some reference to this important
topic, this chapter will deal briefly with some of the devices and some of
the methods which have been worked out to translate into commands the
decisions taken on the basis of radar information. 1
It is to be emphasized that this subject is at least as difficult and as
important as that of the technical design of the radar itself, and far less
well understood. We can now build reliable radar equipment whose
principal performance limitation arises because the earth is round; the
major improvements to be looked for in the use of radar over the next
few years will lie, for the most part, not in the category of technical radar
design, but in the field of fitting the entire radar system, including its
operational organization, to the detailed needs of the use and the user.
EXTERNAL AIDS TO RADAR USE
7.2. Aids to Individual Navigation.-The most frequent and important
use made of radar is as an aid to air and sea navigation. The
resemblance of the PPI display of a modern microwave radar set to a
chart is striking, and suggested very early that navigation would be
assisted by a device that enabled a map of the proper scale to be super-
1The problem of devisingan organizationfor using radar informationin navigation
is discussedin Vol. 2 of the Series.