There are $100 baseball radar guns available for testing your device. Unfortunately, the test may be successful, costing you $100. You may want to "de-tune" the device and gradually tune it up so that you don't immediately burn it out. Alternatively, try it at a long distance -- e.g., half-mile (?), and then bring it closer. https://www.dickssportinggoods.com/products/baseball-radar-guns.jsp https://www.opticsplanet.com/radar-guns.html BTW, you've just designed a very cheap totally *passive* wireless anemometer, that you read by shining your radar gun at it. You should also be aware that with cheap 5GHz wifi and SDR radio components, you can build nifty things at home very inexpensively. https://hackaday.io/project/147-ism-s-band-lfmcw-radar-prototype/log/238-ear... https://hackaday.io/projects?tag=radar https://hackaday.com/2014/02/24/guest-post-try-radar-for-your-next-project/ https://luigifreitas.me/2018-11-23/software-defined-radar-cw-doppler-radar-w... Also, due to the volume applications of radar today, you can buy quite inexpensive 60GHz components to play with. https://www.embedded.com/why-60ghz-mmwave-is-moving-into-the-mainstream/ -----Original Message-----

From: Bill Gosper <billgosper@gmail.com> Sent: Jan 2, 2020 2:02 PM To: math-fun@mailman.xmission.com Subject: [math-fun] There are other kinds of corner reflector?

E.g., square? big-red-buoy-removed-from-florida-beach-after-sitting-there-for-days <https://www.foxnews.com/us/big-red-buoy-removed-from-florida-beach-after-sitting-there-for-days> (Kids, check out https://en.wikipedia.org/wiki/Corner_reflector . Three bounces and the laser beam returns to its source. But likewise, a bundle of *uncolilmated* beams!

I've always wanted to put an anemometer made of corner reflectors on my car to confuse the heck out of police radar. Radar return ordinarily drops off with the *fourth power* of distance. But only 2nd power with a corner reflector. That's huge. Stealth in reverse. Radar transmitters are loud. In the 60s, I worked at a naval air station where a visiting photographer was severely burned when all the flashbulbs <https://upload.wikimedia.org/wikipedia/commons/f/fa/Brownie_Hawkeye_with_Flash.jpg> went off in his pockets. (That sparkly stuff is "magnesium wool"!)) —rwg