RADAR TRACKING SYSTEM CONCEPT AND APPLICATION

ABSTRACT

A classical rotating air surveillance radar system detects target echoes against a background of noise. It reports these detections (known as "plots") in polar coordinates representing the range and bearing of the target. In addition, noise in the radar receiver will occasionally exceed the detection threshold of the radar's Constant false alarm rate detector and be incorrectly reported as targets (known as false alarms). The role of the radar tracker is to monitor consecutive updates from the radar system (which typically occur once every few seconds, as the antenna rotates) and to determine those sequences of plots belonging to the same target, whilst rejecting any plots believed to be false alarms. In addition, the radar tracker is able to use the sequence of plots to estimate the current speed and heading of the target. When several targets are present, the radar tracker aims to provide one track for each target, with the track history often being used to indicate where the target has come from.

When multiple radar systems are connected to a single reporting post, a multiradar tracker is often used to monitor the updates from all of the radars and form tracks from the combination of detections. In this configuration, the tracks are often more accurate than those formed from single radars, as a greater number of detections can be used to estimate the tracks. In addition to associating plots, rejecting false alarms and estimating heading and speed, the radar tracker also acts as a filter, in which errors in the individual radar measurements are smoothed out. In essence, the radar tracker fits a smooth curve to the reported plots and, if done correctly, can increase the overall accuracy of the radar system. A multisensor tracker extends the concept of the multiradar tracker to allow the combination of reports from different types of sensor - typically radars, secondary surveillance radars, identification friend or foe (IFF) systems and electronic support measures (ESM) data. A radar track will typically contain the following information.

TABLE OF CONTENTS

CERTIFICATION PAGE………………………………………………………..2

DEDICATION3

ACKNOWLEDGEMENT4

ABSTRACT5

TABLE OF CONTENTS6

CHAPTER ONE8

1.0INTRODUCTION8

1.1STATEMENT OF PROBLEM8

1.2PURPOSE OF THE STUDY8

1.3IMPORTANCE OF THE STUDY9

1.4DEFINITION OF TERMS9

1.5ASSUMPTION OF THE STUDY9

CHAPTER TWO10

2.0LITERATURE REVIEW10

2.1ROLE OF THE RADAR TRACKER10

2.2GENERAL APPROACH12

2.3PLOT TO TRACK ASSOCIATION14

CHAPTER THREE17

3.0TRACK INITIATION17

3.1TRACK MAINTENANCE18

3.2TRACK SMOOTHING18

Alpha-beta tracker19

Kalman filter19

CHAPTER FOUR21

4.0MULTIPLE HYPOTHESIS TRACKER (MHT)21

4.1INTERACTING MULTIPLE MODEL (IMM)21

4.2NONLINEAR TRACKING ALGORITHMS22

Extended Kalman filter (EKF)22

Unscented Kalman filter (UKF)23

Particle filter24

CHAPTER FIVE25

5.0CONCLUSION25

5.1 LIMITATION OF THE STUDY25

5.2 SUGGESTION FOR FURTHER STUDIES25

REFERENCES27