TX / RX audio over ultrasonics FREQ's? Apparently, I'm not the only one trying.

[ThaDood]

https://blog.vinu.co.in/2018/03/ultrasonic-audio-transmitter-and.html?m=1     I know... Folks are going to tell me that the US Navy has been doing this for decades for underwater COMM's. However, I've wanted to do this over land. The last time that I did was nearly 25 years ago, and that project went up in smoke, literally. In theory, ultrasonic sound waves, (US), would propagate very much like RF microwaves, except any flat surfaces would reflect them, not just metal. That also means that rough and porous surfaces would be just as absorbent and attenuating. Still, the idea of putting US transducers, on solid satellite dishes, and bouncing signals to someone off of water towers, buildings, VERT mountain peaks, and even airplanes, just sounds like a fascinating concept to me. One other factor is the lag time of US from point 'A' to point 'B'. That, can be calculated. And, elevation... US will travel further at sea level's 14.7psig, than at a high elevation. Also in theory, rain scatter is possible with US, as it is with RF 10GHz, and above. Anyone will to try this project?

[Charlie_Dont_Surf]

I don't know but maybe you can get a QSL card out of whatever happens.