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ECE 422: RADAR ENGINEERING AND

NAVIGATIONAL AIDS

Dr. K.Murali Krishna

B.Tech., M.E., Ph.D, MISTE, MIEEE, Fellow IETE

Professor

Department of Electronics and Communication Engineering

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ECE 422 RADAR ENGINEERING AND NAVIGATIONAL AIDS

1. Radar Equation, Radar Block Diagram and Operation, Prediction of Range, Minimum Detectable Signal, Receiver Noise, Probability Density Functions, S/N, Integration of Radar Pulses, Radar Cross-section, Transmitter Power, PRF and Range Ambiguities, Radar Antenna Parameters, System Losses and Propagation Effects.
2. MTI and Pulse Doppler Radar: Introduction, Delay line Cancellers, Moving target Detector, Limitation to MTI performance, MTI from moving platform, Pulse Doppler Radar
3. Tracking Radar, Sequential Lobing, Conical Scan, Monopulse tracking Radar, Low angle tracking, Pulse compression, Block Diagrams of Synthetic Aperture Radar (SAR), Phased array Radars,. MST Radar, ECM, ECCM
4. Radar Receiver, Mixers, Radar Displays, Receiver Protectors.
5. Principles of Direction Finders, Aircraft Homing and ILS, Radio Altimeter, LORAN, DECCA, OMEGA, Inland Shipping Aids. Text Book:
6. "Microwave and Radar Engineering" by Gottapu Sasi Bhushana Rao, ISBN – 978813179944 Pearson Education Chennai 2013.
7. Radar Engineering and Fundamentals of Navigational Aids, G S N Raju, IK International Publishers, 2008 References 1.Introduction to Radar Systems, Skolnik, McGraw Hill, 2007.
8. Foundations For Microwave Engineering, R. R. Collin, McGraw Hill.
9. Microwave Communications – Components and Circuits, E. Hund, McGraw Hill. 4. Microwave Devices and Circuits, S. Y. Liao, PHI. 5. Microwave Engineering, R. Chatarjee, East – West Press Pvt. Ltd.

RADAR

1. Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects.
2. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.
3. A radar transmits radio waves or microwaves that reflect from any object in their path.

Introduction R = ct/2 meters.

Applications

1. Navigational aid on ground and sea
2. Radar altimeters (height measurement)
3. Radar blind lander (aircraft landing during poor visibility)
4. Airborne radar for satellite surveillance
5. Space applications like planetary observations
6. Police radars (Law enforcement and Highway safety)
7. Radars for determining speed of moving targets
8. Remote sensing (weather monitoring)
9. Air traffic control (ATC) and Aircraft safety
10. Ship safety
11. Non-contact method of speed and distance in industry

Military Applications:  Detection and ranging of enemy targets even at night  Aiming guns at aircrafts and ships  Bombing ships, aircrafts, or cities even during night  Early warning regarding approaching aircrafts or ships  Directing guided missiles  Searching for submarines, land masses and buoys

• Monostatic radar

The distance of the target can be calculated

from the total time (t) taken by the pulse to

travel to the target and return to its original

initial point.

Assuming ‘ c ‘ to be the velocity of light in free

space, the distance traversed by pulse is ‘ct’

meters. Now this is 2 times the target distance,

hence the distance to the target

R = ct/2 meters.

Radar frequency band designations Band designation Nominal frequency range Specific radar bands based on ITU assignment HF 3 – 30 MHz VHF 30 – 300 MHz 138 - 144, 216-225 MHz UHF 300 – 1000 MHz 420 - 450, 590-942 MHz L 1 – 2 GHz 1215 - 1400 MHz S 2 – 4 GHz 2300 - 2500, 2700-3700MHz C 4 – 8 GHz 5250 - 5925 MHz X 8 – 12 GHz 8500 - 10680 MHz Ku 1 2– 18 GHz 13.4-14, 15.7-17.7 GHz K 18 – 27 GHz 24.05-24.25 GHz Ka 27 – 40 GHz 33.4-36 GHz

Introduction

• Radar → Radio detection and ranging
• Radar is an electromagnetic system for the detection and location of objects.
• It operates by transmitting a particular type of waveform (ex: pulse modulated sine wave) and nature of the echo signal.
• Radar has advantage of being able to measure the distance or range to the object. This is probably its most important attribute.
• Radar has is used to extend the capability of one’s senses for observing the environment, especially the sence of vision.

Two types of radar

Monostatic - transmitter and receiver use same

antenna

Bistatic - transmitter and receiver antennas are separated

• Modulation Types

– Simple Pulse; one or more repetition frequencies

– Frequency Modulation FM (radar altimeters)

– Pulse with Chirp (pulse compression)

– CW (continuous wave) - police radar (Doppler)

The simple form of the radar range equation

• Radar equation relates the range of radar to

the characteristics of transmitter (T

x

receiver (R

x

), antenna , target and

environment.

• It is useful not for determining the range

from radar to target it can serve both for

understanding radar operation and basis for

radar design.