Simplifier

Okay, let's break this down in a way that's easy to understand. Radar doesn't actually "hear" sound waves like we do. Instead, it sends out radio waves, kind of like a shout, and then "listens" for those waves to bounce back. Now, imagine you're throwing a ball at a moving car. If the car is coming towards you, the ball hits it sooner than if the car was standing still. And if the car is moving away, the ball takes longer to reach it. Radar does the same thing with radio waves. When it sends out a wave that hits something moving, the wave bounces back with a slightly different frequency. This change in frequency is called the Doppler shift. The radar uses this shift to figure out how fast the object is moving, and whether it's coming closer or moving away. So, the radar isn't directly picking up the sound from your "digital tuning fork." Instead, the speaker in your phone is vibrating, and that vibration is what the radar is "seeing." The radar measures the Doppler shift from the moving speaker and calculates a speed based on that shift. The specific frequency of the sound (4672Hz) doesn't matter to the radar; it's only concerned with the movement of the object reflecting the radio waves.

Signal Processing Hobbyist

Alright, let's break down how a radar unit might be interpreting audio as a Doppler shift. The key here is understanding that the radar isn't directly "hearing" the sound. It's detecting minute movements or vibrations caused *by* the sound waves. Think of it this way: the radar emits a 24.150 GHz signal. If that signal bounces off a perfectly stationary object, the reflected wave will have the same frequency. However, if the object is moving, even slightly, the reflected wave will experience a Doppler shift. Now, what could be moving? In your case, it sounds like the radar is picking up vibrations from the "digital tuning fork" – specifically, the speaker cone in your phone. Even though the cone's movement is tiny, it's enough to impart a slight Doppler shift on the reflected radar signal. The radar unit then measures this frequency shift and calculates the corresponding velocity. The 4672 Hz audio signal is indirectly causing a vibration that the radar interprets as movement. The 65 mph reading is just the radar's interpretation of the frequency shift it's detecting, based on its programmed parameters. It's not a direct measurement of the audio frequency itself, but rather the velocity equivalent of the Doppler shift caused by the vibrating speaker.

Network Engineer

As a network engineer, my expertise lies in data transmission and signal processing, not radar technology. However, I can offer some insight based on my understanding of wave phenomena and signal analysis. Radar systems operate by emitting radio waves and analyzing the reflected signals. Doppler shift, the change in frequency of a wave in relation to an observer who is moving relative to the wave source, is a key principle in radar speed detection. The radar unit emits a signal at 24.150 GHz. When this signal bounces off a moving object, the reflected signal's frequency changes slightly. This change in frequency is directly proportional to the object's speed. The 4672 Hz sound wave you mentioned is likely modulating the reflected radar signal. This modulation introduces sidebands around the carrier frequency (24.150 GHz). The radar receiver then interprets these sidebands as a Doppler shift, even though the shift isn't caused by the object's physical movement but by the sound wave's influence on the reflected signal. The radar system is essentially "tricked" into thinking it's detecting a specific speed based on the frequency shift it perceives.