Doppler Effect

Skolnik — Doppler Frequency Shift in Radar

Radar

Target

Pulse-Doppler

Computed

Wavelength λ
Doppler fd
Effective velocity
Unambiguous vmax
Velocity resolution
Doppler Shift
fd = 2v cos(θ) / λ

Approaching (↗) → positive fd
Receding (↘) → negative fd

PRF limits:
vmax = λ PRF / 4
Velocity aliasing if |fd| > PRF/2