Radar Observes the Weather

By Louis J. Battan | Go to book overview
Save to active project

CHAPTER 2
PRINCIPLES OF RADAR

Some radar sets are quite weak and emit less power than is used in an ordinary light bulb. Others are so powerful that for very short periods of time the power transmitted could light up an entire town. But in principle they are much the same. They all contain a transmitter, a receiver, an antenna, and an indicator. We shall return to a description of these components, but before doing that, let us see how radar measures the distance to any object, for example, an airplane.

The radar set sends out a pulse of energy in the direction of the airplane (Fig. 1). A small fraction of the energy is reflected back and is detected by the radar. If one knows the speed at which the pulse travels and the time elapsed between transmission and reception of the pulse, one can easily calculate the distance to the airplane. In all radar sets the pulse of energy is in the form of electromagnetic waves, which for most practical purposes can be considered to move at a constant velocity equal to 186,000 miles/sec (5 × 108 meters/sec). Some readers will immediately recognize that this is the velocity of light.

-21-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited page

Bookmark this page
Radar Observes the Weather
Settings

Settings

Typeface
Text size Smaller Larger
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen
/ 160

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?