Abbot’s Cliff Acoustic Mirror

Acoustic Mirror, Abbot's Cliff

Acoustic Mirror, Abbot’s Cliff

Date

10 February 2013
Location

Abbot’s Cliff, Folkestone, Kent

TR 27188 38605; 51.10170°N, 1.24369°E

Information

Before the advent of radar, there was an experimental programme during the 1920s and 30s in which a number of concrete sound reflectors, in a variety of shapes, were built at coastal locations in order to provide early warning of approaching enemy aircraft. A microphone, placed at a focal point, was used to detect the sound waves arriving at and concentrated by the acoustic mirror. These concrete structures were in fixed positions and were spherical, rather than paraboloidal, reflectors. This meant that direction finding could be achieved by altering the position of the microphone rather than moving the mirror.

The acoustic mirror at Abbot’s Cliff is located on the cliff top almost midway between Folkestone and Dover.

Acoustic mirror (Wikipedia);
Abbot’s Cliff sound mirror (Andrew Grantham)

Acoustic Mirror, Abbot's Cliff

Acoustic Mirror, Abbot’s Cliff

Concrete structure with the acoustic mirror in the background (middle right)

Concrete structure with the acoustic mirror in the background (middle right)

Looking out from the concrete structure

Looking out from the concrete structure

Acoustic mirror

Acoustic mirror

Acoustic mirror

Acoustic mirror

View of Abbot's Cliff from the acoustic mirror

View of Abbot’s Cliff from the acoustic mirror

Advertisements

17 thoughts on “Abbot’s Cliff Acoustic Mirror

  1. These were an odd technological dead end inasmuch as they kind of worked (if the aircraft were close), but then radar came along not long after which was much more effective. Still, they’re interesting things to see, and there seem to be quite a few left!

  2. A wild idea…a long way away from the sensors available to the military today! I love the whackiness of this, and that these structures have lasted, to be adorned with the white noise of graffiti..

  3. Pingback: Iterate cycling goals to fit with the day to day. | monaxle

  4. Pingback: Fan Bay Sound Mirrors | GeoTopoi

Share your thoughts...

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s