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User:Crecasens

466 bytes added, 10:12, 23 July 2013
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The frequency domain signal is the result of applying the FFT to one ramp modulation interval of the 2048 sampled IF radar signal captured samples.<br>
The You can see the spectrum of the radar application takes IF signal in real time thanks to the samples power of one single ramp and completes the rest with zeros (padding) completing 2048 samplesOMAP processor, and it performs the FFT over these 2048 samples, resulting by clicking on the spectrum of the signal with 2048 points resolution. "F(jw)" icon:
<br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [[Image:WEB_HOME_PAGE_F(jw)_NEW.jpg]] The radar application takes the samples of a single ramp and, if needed, it completes the rest with zeros (padding), thus completing the 2048 samples. Then it performs the FFT over these 2048 samples, resulting on the spectrum of the signal with 2048 points resolution:
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [[Image:WEBFFT_2m_-FFT3mBT_600_NEWs.jpg]]<br>
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Following our example, the above picture shows the FFT of the measurement. Y axis represents signal strenght and X axis represents the FFT sample. Note that only the 300 500 first samples are shown.
We can see a dominant peak centered about sample number 16. This peak should correspond to the measured dominant sinus of 4,609KHz on time domain graphic.<br>
We can see other small peaks at about samples 40 and 50. These peaks are due to other reflections on the room at a longer distance. So here an example of the possibilities of the radar to detect several targets at different distances. But by the moment is better if we pay our attention on a single target scenario to keep learning about the radar signal and later we will be able to analyse more complex scenarios.
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== Compare Measurements ==
Carles Recasens
646
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