Howtosignalprocessing
- How does pulse Doppler radar work?
- What is Doppler ambiguity?
- What is Doppler FFT?
- How does Doppler radar measure velocity?
How does pulse Doppler radar work?
In pulse Doppler radar, the range is estimated by binning the returns of the individual pulses by their time of arrival, which is proportional to the range. The Doppler processing is done by coherently measuring the phase shifts across many pulses. In this way, both range and velocity of targets can be determined.
What is Doppler ambiguity?
In pulse radar, the modulation of the carrier frequency is a periodic sequence of rectangular pulses. The frequency spectrum of the transmitted signal is a comb-shaped line spectrum. The line spacing of the spectrum is equal to the Pulse Repetition Frequency fPRF or PRF.
What is Doppler FFT?
FFT Plot (Range-Doppler Plot): The FFT is used to convert radar time domain data to frequency domain. Detected objects and their Doppler signature are plotted in an FFT Plot. The x-axis represents the Doppler Frequency (which can be converted to Doppler Speed), and the y-axis is range.
How does Doppler radar measure velocity?
Velocity data is derived from the phase, or doppler shift of the returned energy. The radar's computers will calculate the shift and determine whether the precipitation is moving toward or away from the radar, and how fast, then apply a corresponding color to those directions and speeds.
