Definition

1. Noun:
   • A type of radar system: Doppler radar is a specialized radar system that uses the Doppler effect to measure the velocity of a detected object relative to the radar unit. It can distinguish between stationary and moving targets.

Usage and Examples

• Noun:
  • Meteorologists rely on Doppler radar to track the speed and direction of storms.
  • The police officer used a Doppler radar gun to check the speed of passing cars.
  • Modern aviation uses Doppler radar for wind shear detection near airports.

Advanced Usage and Technical Context

• "Pulse-Doppler radar": A more advanced type that combines pulse radar techniques with Doppler velocity measurement, commonly used in weather forecasting and military applications.
  • The National Weather Service upgraded its network to dual-polarization pulse-Doppler radar.
• The term is often used in compound nouns specifying its application, such as weather Doppler radar or Doppler radar imagery.

Variants and Related Words

• Radar (n): A general system for detecting objects and determining their distance using radio waves.
• Doppler effect (n): The change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. This is the physical principle the radar is named after.
• Sonar (n): A similar detection system that uses sound waves underwater, which can also utilize the Doppler principle.

Synonyms

• Velocity detection radar: A descriptive synonym emphasizing its primary function.
• Doppler shift radar: A less common variant highlighting the key physical phenomenon it exploits.

Related Technical Phrases

• Doppler velocity: The speed component measured by this radar.
  • The Doppler velocity data indicated strong rotation within the thunderstorm.
• Doppler spectrum: The distribution of velocity measurements from the radar returns.

Notes on Meaning

The core meaning of "Doppler radar" is always tied to its function of measuring velocity via the Doppler shift. It is a compound noun where "Doppler" specifies the technology used by the "radar." It is not used as a verb or in idiomatic expressions.

Noun

1. radar that uses the Doppler shift to measure velocity