Jump to content
Sign in to follow this  
  • entries
  • comments
  • views

Sonar waves



Sonar is an acoustic wave (whose uses are roughly analogous to radar) and whose name is an acronym for "sound navigation and ranging." Sonar consists of pulses of sound waves are transmitted into water, usually at ultrasonic frequencies in the range of 20-100 kHz. They travel out and are reflected by a solid object. The reflected signals are detected and then correlated to give the operator an indication of the distance and bearing of the object.

There are some fundamental differences to note between sonar and radar. First, the frequencies used for sound are much lower, since sound is highly attenuated at frequencies higher than 100 kHz. Secondly, the speed of sound (331m/s) in water is much slower than that of a radio wave in air, so the time between the transmitted and received pulses is much greater for sonar. Thus the correlation needed to determine bearing is different. Thirdly, the speed of sound in water varies with depth, temperature, and even salinity, and all these parameters need to be known for accurate determinations.


Recommended Comments

There are no comments to display.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Terms of Use

The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.

Copyright Notice

APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including non-profit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to info@aplusphysics.com. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.

  • Create New...