INTRODUCTION TO BASIC RADAR SYSTEMS
Upon completing this chapter, you should be able to do the
1. Describe basic radar concepts.
2. Identify equipment requirements for basic radar systems.
but which are scheduled for replacement, are not dis-
This chapter discusses radar principles and basic
radar systems that you may encounter as a Fire Con-
trolman at your command. The Navy Electricity and
Electronics Training Series (NEETS), especially
Module 18, Radar Principles, NAVEDTRA 172-18-
00-84, provides information that is basic to your
understanding of this chapter. You should, therefore,
refer to NEETS Module 18 and to Electronics Instal-
lation and Maintenance Book, Radar, N A V S E A
SE000-00-EIM-020, on a regular basis to ensure that
you have a complete understanding of this subject
As a Fire Controlman Second Class, and a pos-
sible work-center supervisor, you must understand the
basic radar principles and safety requirements for
radar maintenance. However, your first assignment
may not afford you exposure to radar systems.
This chapter is not designed to teach you every
radar system the Navy uses, but simply to familiarize
you with the radars and their general characteristics.
Because there are so many different models of radar
equipment, this chapter describes only the radars and
radar accessories that are used in the fleet today. Older
radar systems that are currently installed in the fleet,
BASIC RADAR CONCEPTS
The term radar is an acronym made up of the
words radio, detection, and ranging. It refers to elec-
tronic equipment that detects the presence, direction,
height, and distance of objects by using reflected
electromagnetic energy. The frequency of electromag-
netic energy used for radar is unaffected by darkness
and weather. This permits radar systems to determine
the position of ships, planes, and landmasses that are
invisible to the naked eye because of distance, dark-
ness, or weather.
Radar systems provide only a limited field of view
and require reference coordinate systems to define the
positions of detected objects. Radar surface angular
measurements are normally made in a clockwise
direction from true north, as shown in figure 1-1, or
from the heading line of a ship or aircraft. The actual
radar location is the center of this coordinate system.
Table 1-1 defines the basic terms in figure 1-1 that
you need to know to understand the coordinate sys-