"Doppler radar" . "doppler RADAR" . "Doppler navigation" . . "doppler navigation" . . . . "Doppler navigation radar" . . . . "Doppler navigational radar" . "doppler navigation radar" . . . "Doppler signals" . "Dopplar" . . "Doppler" . . "Doppler radar" . . "Doppler velocity" . "doppler ranging radar" . "doppler" . "landing radar" . . . "doppler radar" . "Doppler RADAR" . . "Doppler_radar#History" . "doppler tracking radar" . "Doppler technique" . "microwave Doppler tracking" . . . . . "Doppler Radar" . . . . . "Doppler beacons" . . "Pulse-Doppler" . "radar" . "Doppler filtering" . . . "Doppler effect" . . . .