Radar System Engineering

CHAPTER 6
THE GATHERING AND PRESENTATION OF IUDAR DATA
BY L. N. RIDENOUR,L. J. HAWORTH, B. V. BOWDEN, E. C. POLLARD
6.1. Influence of Operational Requirements. I—The purpose of any
radar system is to present information on the positions of targets within
the volume of space it surveys. The nature of such targets, their
number, and the character of the information required about them will
depend profoundly on the function which the radar is called upon to
perform. For example, the radar altimeter used in aircraft deals with
only one target—the surface of the earth beneath the planeand offers
only one datum—the minimum distance of the altimeter from that target.
A radar system used for control of air traffic near a landing field, on
the other hand, must display the range, bearing, and altitude of all
aircraft within or near the boundaries of the control zone. At a given
moment, there may be more than a hundred individual targets, for
each of which the radar must provide sufficiently accurate positional
information to enable controllers to issue prompt instructions to pilots.
Radar equipments suitable for such different purposes will present
wide differences in design. This chapter and the next deal with the
principal fundamental differences that appear in various conventional
pulse radar designs. In this chapter the effect of operational requirements
on the design of the radar itself is considered; in the next is discussed
the more difficult question of organizing the facilities and services
required to interpret and make use of the data provided by radar.
The most important and fundamental of the radar design differences
that arise from different functional requirements are those which concern
the beam pattern produced by the antenna, the arrangements for
scanning a certain volume of space with that beam, and the indicator or
indicators necessary to display the positions of targets detected. Because
of the extremely close interrelationship among these three factors, and
because all three are principally determined by the functional aim of the
radar equipment, it would appear desirable to begin with a discussion of
the various radar functions, showing for each the choice of these three
factors which experience has so far recommended. Without an appropriate
introduction, however, such a treatment might be hopelessly
confusing. Accordingly, there follows a catalogue of existing indicator
I By L. N. Ridenour.
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