Mark Denny

I'm a science writer, and my books explain how things work.

. (2) Blip, Ping and Buzz: Making sense of radar and sonar

I spent almost 20 years in this field, as a radar systems engineer and a sonar systems analyst. It seemed to me that there were no popular-level books that explained the subject adequately, so here is my account of the historical development, capabilities and future direction of radar and sonar systems.

Sidescan sonar image of a century-old shipwreck, the steam packet SS Portland, lost outside Boston in 1898. Dark areas correspond to acoustic shadows, which convey information about the third dimension. Image courtesy of Klein Associates.

The Portland--known as the 'Titanic of New England'--sank in a 'perfect' storm, with 100 mph winds and 60 foot waves, along with 190 passengers and crew. She lies at a depth of 460 feet and has only recently been visited by divers, though her location has been known (from sonar imaging) since 1989.


"Overall this is an impressive, enjoyable and unique book. Denny, who has spent the bulk of his career in radar and sonar research...has succeeded in giving insight into both the scientific principles and the history behind radar and sonar, using conceptual and pictorial descriptions rather than pages of equations. The style is light and entertaining [and] achieves the rather special trick of being valuable both to the non-specialist and to the seasoned practitioner." Prof. Hugh Griffiths, Cranfield University, in Physics World (May 2008). 

"Mark Denny has done a great job with this book...It is highly recommended for just about everyone including, dare I say it, experts." Richard J. Peppin, Scantek, Inc. in International Journal of Acoustics and Vibration (March 2008).

"The writing style is clear and sometimes whimsical, making for easy reading...Blip, Ping and Buzz is an excellent addition to the ever-popular genre of books about how things work." Colin Keay in Australian Physics (February 2008).

"Denny keeps his text accessible to the non-technical...Along the way he supplies extremely clear and helpful graphics..." Book News (December 2007).

For more reviews see the publisher's website:

and the website:

Additional material:

In chapter 4 I included a dramatic picture of a German U-boat under attack from the air. That photo, and this one of a U-boat surfacing (or plowing through heavy seas), were kindly provided by Captain Jerry Mason, U.S.N. (ret'd).

 A composite weather radar image, superimposed on a map of the United States. The National Weather Service publishes these maps online (plus more detailed maps for each state) updated every day. Images such as this one are so familiar to us that we may become very ho-hum about the underlying technology. Modern weather radar can provide information on precipitation rates, wind velocity profiles, cloud height and coverage, and other useful data. The data from many weather radar sites is integrated to produce a map such as this one.