📡 Doppler Weather Radar

Target speed 30 m/s Target direction 180° PRF (sets Nyquist) 1000 Hz Radar frequency 5.6 GHz Number of cells 6 Display product

Velocity

Reflectivity

Presets

Approaching storm

Rotation couplet

Tangential (0 Doppler)

Aliasing demo

Radial velocity0 m/s

Doppler shift Δf0 Hz

Nyquist velocity0 m/s

Aliased?no

Range to selected— km

A pulsed Doppler radar senses only the radial velocity (toward/away). The shift is Δf = 2·v_r·f / c. Toward the radar reads green/blue, away reads red — exactly like operational Doppler velocity products. A target moving tangentially (across the beam) has v_r=0 and shows no Doppler. The pulse rate (PRF) caps the unambiguous velocity at the Nyquist velocity v_N = PRF·λ/4; beyond it the velocity aliases and folds to the wrong sign — the classic radar "purple haze". Click a cell to read its values.

PPI display — radar at centre, sweep colours radial velocity (green toward, red away). Vectors show true target motion.