This has been on my to-do list since forever! Nice work Ben Wang.
Phased Array Microphone (2023)
81–90 of 191 posts
Re: Phased Array Microphone (2023)
#82Earlier quoted context omitted.
Is that the same thing where a flat-earther tried to measure something with an expensive laser gyro and kept finding that Earth was rotating?
I think the most you can tell from an IMU or gyro is that there is a change in velocity in a direction aligning with East-West when there is a change in location and that the change in velocity is greater when the location changes in line with North-South. The change in velocity would be greater as one approaches the poles and lesser at the equator. Thought experiment: if I zeroed my IMU at the North pole and travele…
The flat earther used a fibre optic gyro. You don't "zero" it, it continuously outputs a measurement of its own angular rate around it's sensitive axis. For a 3-axis gyro placed still on earth, it will read about 15 degree/hour around wherever the axis of earth is oriented.
Re: Phased Array Microphone (2023)
#83"As part of the calibration, the speed of sound is also a parameter which is optimized to obtain the best model of the system, which allows this whole procedure to act as a ridiculously overengineered thermometer." Reminds me of the electronics adage: "all sensors are temperature sensors, some measure other things as well."
Is there one saying “All electronic devices are smoke machines, some can compute too”?
"All electronics are hand-warmers if miscalibrated correctly enough."
Re: Phased Array Microphone (2023)
#84Re: Phased Array Microphone (2023)
#85Earlier quoted context omitted.
Didn't Israeli students show that you can recover audio from the vibrations of bulb filament with a fast photo diode? I'd test that with a CCD line sensor plus a wide aperture lens and reading it out with 8kHz. Then you have 128 audio pixels that can cover an entire city.
Line of sight might be an issue there. I'm thinking more high-end clandestine eavesdropping. Fun fact: curtains are a pretty good defeat for laser microphones, but if the building is really old and made of solid stone, you can point at the rock instead!
The rock?! That’s incredible. I would have guessed it was too dense to pick up normal speaking volume. Then again, even the window glass vibration seems pretty magical to me.
Re: Phased Array Microphone (2023)
#86"As part of the calibration, the speed of sound is also a parameter which is optimized to obtain the best model of the system, which allows this whole procedure to act as a ridiculously overengineered thermometer." Reminds me of the electronics adage: "all sensors are temperature sensors, some measure other things as well."
Oh yeah. I realised this the day I discovered my fancy digital SLR was a thermometer: https://entropicthoughts.com/does-my-dslr-have-dead-pixels
A lot of people like myself consider heat a form of light but I guess a photographer would be just thinking visible light. They say that about 50% of the sun's light emissions comes in the infrared frequencies.
Re: Phased Array Microphone (2023)
#87Earlier quoted context omitted.
"All diodes are light-emitting if you try hard enough"
All diodes are also light SENSING is you try hard enough.
You don't have to try hard. Just use it as a photodiode and it magically works. However, if it's inside a plastic case that blocks light, it doesn't.
Due to some law about entropy, efficient processes are necessarily reversible. That's why electric motors - some of the most efficient machines ever invented - are also generators.
Re: Phased Array Microphone (2023)
#88Re: Phased Array Microphone (2023)
#89Re: Phased Array Microphone (2023)
#90Could this be combined with a smaller number of high quality mics and then machine learning or something else incorporating them to boost the overall quality while maintaining all the other features?