Main Radar Home

Radar theory Home

AP3302 Pt3 Contents

AP3302 Pt3 Section 1 Contents

 Contact the Editor

AP 3302 Pt. 3

Section 1

CHAPTER 1

PULSE-MODULATED RADAR

screen. This arrangement is illustrated in Fig 19. To ensure a bright, clear picture the c.r.t. screen has a long 'afterglow'. Thus when an echo is 'painted' it remains bright until the trace comes round again to re-paint it.

The display described is known as a plan position indicator (p.p.i.). The distances of the echoes from the centre of the screen indicate the ranges of targets, and the angular position of each echo indicates the bearing in plan or 'in azimuth' of the corresponding target. Such a display is in effect a 'radar map'. Fig 20 shows a typical picture on the p.p.i. of a ground search radar.

How the Height of a Target is Determined

So far we have seen how a target can be detected and how its range and azimuth bearing can be found. We are thus a long way towards pin-pointing the position of a target in space. The only factor missing, if the target is an aircraft or a missile, is the height of the target. A radar installation which indicates range, bearing and height of a target gives, in effect, a three-dimensional


Previous page

To top of this page

Next Page

Constructed by Dick Barrett
Email:
editor@ban_spam_radarpages.co.uk

(To e-mail me remove "ban_spam_" from my address)

ęCopyright 2000 - 2002 Dick Barrett

The right of Dick Barrett to be identified as author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.