Presentation

1. Radar Principles & Systems With your facilitator, LT Mazat

2. I. Learning Objectives A. The student will comprehend the basic operation of a simple pulse radar system. B. The student will know the following terms: pulse width, pulse repetition frequency, carrier frequency, peak power, average power, and duty cycle. C. The student will know the block diagram of a simple pulse radar system and will comprehend the major components of that system.

3. D. The student will comprehend the basic operation of a simple continuous wave radar system. E. The student will comprehend the concept of doppler frequency shift. F. The student will know the block diagram of a simple continuous wave radar system and will comprehend the major components of that system, including amplifiers, power amplifiers, oscillators, and waveguides.

4. G. The student will comprehend the use of filters in a continuous wave radar system. H. The student will know the fundamental means of imparting information to radio waves and will comprehend the uses, advantages, and disadvantages of the various means. I. The student will comprehend the function and characteristics of radar/radio antennas and beam formation.

5. J. The student will comprehend the factors that affect radar performance. K. The student will comprehend frequency modulated CW as a means of range determination. L. The student will comprehend the basic principles of operation of pulse doppler radar and MTI systems.

8. Pulse Transmission

12. Determining Range With Pulse Radar c = 3 x 10 8 m/sec t is time to receive return divide by 2 because pulse traveled to object and back

15. Pulse Radar Block Diagram Power Supply Synchronizer Transmitter Display Duplexer (Switching Unit) Receiver Antenna Antenna Bearing or Elevation Video Echo ATR RF TR

17. Doppler Frequency Shifts Motion Away: Echo Frequency Decreases Motion Towards: Echo Frequency Increases

18. Continuous Wave Radar Components Discriminator AMP Mixer CW RF Oscillator Indicator OUT IN Transmitter Antenna Antenna

21. Modulation

23. Beamwidth Vs. Accuracy

24. Azimuth Angular Measurement

25. Determining Altitude

27. Basic Dipole Antenna and Beam Forming H alf-Wave Dipole Antenna Basic Beam Formed

28. Wave Shaping Linear Array Beam Forming Side Bottom Types of Linear Arrays Broadside Endfire Array

29. Wave Shaping Linear Array Parasitic Element

31. Wave Shaping -Quasi-Optical Systems Reflectors Lenses

33. Questions? Please read Ch 9.

34. Radar Principles and Systems Part II

37. Signal Reception • Only a minute portion of the RF is reflected off the target. • Only a fraction of that returns to the antenna. • The weaker the signal that the receiver can process, the greater the effective range .

49. Summary of Factors and Compromises Summary of Factors and Compromises Pulse Shape Sharp a rise as possible Better range accuracy Require infinite bandwidth, more complex Tall as possible More power /longer range Requires larger equipment/more power Pulse Width Short as possible Closer minimum range Reduces maximum range More accurate range Pulse Repetition Freq. Short Better range accuracy Reduces maximum range Better angular resolution Better detection probability Pulse Compression Uses technique Greater range More complex circuitry Shorter minimum range Power More Greater maximum range Requires larger equipment & power Beam Width Narrow Greater angular accuracy Slow antenna rate, Detection time Carrier Frequency High Greater target resolution Reduces maximum range Detects smaller targets Smaller equipment Receiver Sensitivity High Maximizes detection range More complex equipment Receiver Bandwidth Narrow Better signal-to-noise ratio Distorts pulse shape Factor Desired Why Trade-off Required

53. Questions? Transmission Echo Wasted Echo