Speed Gun

Syllabus: GS3/ S&T

In News

• To combat speeding vehicles, traffic police across India have increasingly adopted speed guns as a crucial enforcement tool to ensure road safety.

About Speed Gun

• Definition: Devices used to measure the speed of moving objects without contact, commonly used by traffic police to enforce speed limits.
• Working:
  • Doppler effect: They rely on the change in frequency of waves (usually radio waves) reflected off a moving vehicle.
  • Higher frequency = approaching: If the vehicle is moving towards the gun, the frequency of the reflected waves increases.
  • Lower frequency = moving away: If the vehicle is moving away, the frequency decreases.
  • Speed Calculation: The gun calculates the speed based on this frequency difference.

Limitations

• Beam Divergence: Radio waves can spread out, potentially measuring the speed of multiple vehicles simultaneously, leading to inaccurate readings.
• Interference: Continuous-wave radar can be affected by reflections from multiple vehicles or other objects, causing errors.
• Cost: Advanced systems are needed to compensate for these limitations, making them more expensive.

Transition to LIDAR Speed Guns

• LIDAR (Light Detection and Ranging): Uses laser light instead of radio waves for better targeting and accuracy.
• Advantages: Minimal beam divergence ensures precise measurements.
  • Superior performance in high-traffic environments.

Source: TH