Learning objectives are stated at the beginning of each chapter. These learning objectives serve as a
preview of the information you are expected to learn in the chapter. The comprehensive check questions
are based on the objectives. By successfully completing the OCC/ECC, you indicate that you have met
the objectives and have learned the information. The learning objectives are listed below.
1. Define range, bearing, and altitude as they relate to a radar system.
2. Discuss how pulse width, peak power, and beam width affect radar performance.
3. Describe the factors that contribute to or detract from radar accuracy.
4. Using a block diagram, describe the basic function, principles of operation, and interrelationships
of the basic units of a radar system.
5. Explain the various ways in which radar systems are classified, including the standard
Army/Navy classification system.
6. Explain the basic operation of cw, pulse, and Doppler radar systems.
INTRODUCTION TO RADAR FUNDAMENTALS
The term RADAR is common in todays everyday language. You probably use it yourself when
referring to a method of recording the speed of a moving object. The term Radar is an acronym made up
of the words radio detection and ranging. The term is used to refer to electronic equipment that detect the
presence, direction, height, and distance of objects by using reflected electromagnetic energy.
Electromagnetic energy of the frequency used for radar is unaffected by darkness and also penetrates
weather to some degree, depending on frequency. It permits radar systems to determine the positions of
ships, planes, and land masses that are invisible to the naked eye because of distance, darkness, or
The development of radar into the highly complex systems in use today represents the accumulated
developments of many people and nations. The general principles of radar have been known for a long
time, but many electronics discoveries were necessary before a useful radar system could be developed.
World War II provided a strong incentive to develop practical radar, and early versions were in use soon
after the war began. Radar technology has improved in the years since the war. We now have radar
systems that are smaller, more efficient, and better than those early versions.
Modern radar systems are used for early detection of surface or air objects and provide extremely
accurate information on distance, direction, height, and speed of the objects. Radar is also used to guide
missiles to targets and direct the firing of gun systems. Other types of radar provide long-distance
surveillance and navigation information.