I am currently trying to create an system to measure wind speed, and I know ultrasound is a good way to do it. I want to make my system be lower cost, however, still maintaining 0.5 m/s precision or better.
There are a few ways I thought to do this.
- Measure time of flight into the wind and time of flight with the wind, and calculate the difference to get wind speed.
- Measure the shift in phase from the emitted signal to the received signal
- Use an ultrasound transducer array to determine how much the transimtted sound wave has shifted due to the wind (system oreinted perpendicular to the wind)
- Measuring intensity of sound with and against the wind.
For method 1, I think I could disassemble and HC-SR04, placing the transducer opposite the emitter. Then I could measure time of flight without reflections. However, the precision is not quite good enough. I want something ~0.5m/s, and it seems like this method will give me ~5m/s. I am wondering if there is a way to improve the precision of this device. Or perhaps there is another device, or other pieces I could use to build my own more accurate version.
For method 2, I'm not sure what electronics I would need to use measure the phase difference. Is there a simply way to measure the phase difference between the output signal and the received signal?
For method 3, I could not find any sensors that are low cost.
For method 4, I believe it should be a 1/r^2 decay, but this may not be a precise enough method.
Please let me know if you have any insight on which methods would work best and how to implement these. Perhaps I would need a combination. I thought about using time of flight to get a coarse measurement and phase shift to refine the measurement
Thanks for the help!