Aircraft detection before radar - video and photo

[Jon]

Aircraft detection before radar; essentially Acoustic mirrors. By the 1930s, incoming aircraft were already too fast to detect with this type of system in time to engage them.

Radar came on the scene just before WWII. Although it made acoustic mirror detection useless, radar pioneers were able to make use of the existing networks of interconnected listening stations.



1:15 video:

[Jon]

More of these. This was a brief, but enthusiastic period of development just before radar. Virtually every military in the world had their own versions. My personal favorite are the Japanese War Tubas, pictured first below:

[Jon]

All of those wacky Seussian listening devices went the way of the dodo when radar technology hit the scene. Here's the first US radar, the SCR-286.

[sossol]

Tom Scott has a great video on the ginormous sound mirrors in England.

[PJs]

Sound and wave propagation is such a fascinating subject to me, but I have to say that I abnormally aspirated my espresso this morning when I saw the 2 Japanese guys with their horned binocular head gear and the expressions on their faces...That pic is Ripe for Memeage! And honestly I would love to hear those giant tuba's bring down the walls Jericho. Using them in reverse would need some wind, but Wow what a sound.

Excellent subject and pics and there is a lot of modern stuff out there for listening and LF propagation. The embassy in Russia comes to mind. Still giggling, though!

[Jon]

It's always easy to over-anthropomorphize, but that first US radar sure looks a lot like the various pre-radar listening devices - but for gathering radio waves instead of sound waves. AFAIK, most modern radar does not follow that huge-ears-with-a-head-in-the-middle design.

This is similar to how some early aircraft were designed to look and function like birds.

[PJs]

It's always easy to over-anthropomorphize, but that first US radar sure looks a lot like the various pre-radar listening devices - but for gathering radio waves instead of sound waves. AFAIK, most modern radar does not follow that huge-ears-with-a-head-in-the-middle design.

This is similar to how some early aircraft were designed to look and function like birds.

In affect you are right they do follow the horn, cone & dish types with similar function at different frequencies, in that the antenna/receivers move with the transmitter to zero in on a spacial area, just like the head mounted and others with alt azimuth capability. Note the use of cones in the 4 petal hexagon flower one third pic from the last, creating an array on each petal to help dial in the direction, probably through some db level comparator system. Again the early radars used a comparator system kind of in the same way. Modern radars still use the basic transmit/receive system but with much more sophisticated antenna design, math, physics and electronics.

It is amazing how we use nature as a sounding board for our early developmental inventions. Even today's slower aircraft wing shapes (profiles) still resemble basic bird wing profiles and aileron feathers. Here is an interesting article I found while back searching for foil design for a VAWT I was kicking around. Note the paragraph "FLUID-STRUCTURE INTERACTION" and how that could be controlled internally by a fluid of unique properties.

Another example is modern tunneling machines and the similarity to how earthworms eat the dirt and excrete mucus to form the walls. Perhaps mimicry is the best form of flattery for our amazing world...hopefully it puts up with us till we figure it out.

Still giggled when I saw the 2 guys...ones grinning and the other doesn't want to be there. Priceless.

PJ

[Jon]

Nice paper. Another way to think of it is that nature is often a proof-of-concept for a technological advancement. A beautiful example is the pre-WWI Taube airplane:



Interestingly, the Taube shape was inspired not by a bird, but by the gliding seeds of Alsomitra macrocarpa. 49-second video:

[PJs]

Very cool seed! Thanks, I hadn't heard of these before, but have played with helicopter seeds (Maple/Sycamore) every chance I get. He (Taube) had obviously also studied birds with his cable driven warping for ailerons and elevators instead of hinges. The Alsomitra macrocarpa seeds may also be a precursor to the flying wing designs of the Horten 229 and Northrop YB/XB designs in WWII with the bat tail similar to the seeds.

You make a good point about Nature being a "Proof of Concept" for our technologies. The ideas of Sacred Geometry and symmetry stemmed from natural shapes and have been around for millennia. I always find it interesting though that Nature has a unique character to each living organism and even how nature shapes hardscapes uniquely with the underlying forms by rules that the sky knows.

Inspiring!

[bruce.desertrat]

"Japanese War Tubas" I immediately imagined some horrific sonic weapon of war...