Hi everybody,
I am a new member here and generally new with Labview.
I am a student and I am running my diploma project which is a construction of a Doppler radar for velocity measurement of a pendulum. I am using 9 GHz signal generator and I am working with wave-guides. Using a power devide T-Type H-plan, i get the signal of the doppler frequency (difference between the propagated signal, and the signal that arrives to the receiver horn which contains doppler shift). then with a crystal detector and through a coaxial cable I can transfer the signal to the oscilator or to the pc using NI PXI-6281 card.
-My first goal is to make the power spectrum of the signal and find the highest peak frequency which corresponds to the highest velocity of the pendulum.
- Final goal is to build a real time graphic wich contains the velocity of the pendulum related to time.
-Until now I have done the attached file but the power spectrum is showing alaways a peak around 34000 (maybe because if the noise) no matter how fast the pendulum is moving (I am also using low pass filter because because of the computer inserts a lot of noise).
-how can i calculate the real frequency (X-scale) to the power spectrum?
-Do you have any ideas how can i build the graphic of the velocity related to the time?
P.S
I have been based on this video
https://www.youtube.com/watch?v=xMWIATas_e0
Thank you a lot in advance!