Bob S said:Could you use some fast Fourier transform (fft) software to measure the doppler pitch change from a moving vehicle? See
http://www.top4download.com/free-fft-analysis/
Bob S
dmtr said:Here is a nice link for you: "Hacking the Hot Wheels Radar Gun"
http://www.edparadis.com/radar/
Note that the micro controller on that device can easily be reprogrammed using the open source software tools. It is also very cheap, only $30 :)
The Doppler Effect is a phenomenon in which the frequency of a wave (such as sound or light) appears to change when the source of the wave is moving relative to the observer.
The Doppler Effect works by causing the waves emitted by a moving source to compress or stretch, depending on the direction of motion. This compression or stretching changes the wavelength and frequency of the wave, resulting in a perceived change in pitch or color.
The Doppler Effect is used in radar and sonar technology to measure the speed and direction of moving objects, such as airplanes and ships. It is also used in medical ultrasound to create images of internal structures and in astronomy to measure the motion of distant celestial objects.
You can demonstrate the Doppler Effect by using a simple experiment with a sound source (such as a whistle) and an observer (such as a person). Have the sound source move towards or away from the observer, and listen for the change in pitch as the distance between them changes. You can also use a physics simulation software to demonstrate the Doppler Effect with visualizations.
The factors that affect the Doppler Effect include the speed and direction of the source and observer, the speed of the wave, and the distance between the source and observer. The medium through which the wave is traveling can also affect the Doppler Effect, as different mediums can cause different amounts of compression or stretching. Additionally, the relative motion between the source and observer plays a role in the perceived change in frequency.