What is the Difference Between Radar and Lidar?

Article Series: How LTI Lasers Work

Radar and lidar are the two most common technologies used for traffic safety applications. When evaluating traffic safety products such as handheld speed guns, understanding the difference between these technologies ensures the right solution for your specific needs. Essentially, each technology uses different energy wavelengths to get the job done.

What is Radar?

Radar is an acronym that stands for Radio Detection and Ranging. This technology uses radio waves to calculate the distance of an object. A sensor transmitting device measures the distance of an object using the length of time it takes for the radio waves to reflect and return to the device.

Commonly used for speed enforcement, other radar applications include:

• Air traffic control
• Air defense systems
• Antimissile systems
• Aircraft anti-collision systems
• Ocean surveillance
• Outer space surveillance
• Meteorological precipitation monitoring
• Altimetry and flight control systems
• Guided missile target locating systems

Radar waves are a lower frequency and longer wavelength than the light waves associated with lidar. Because of this, several limitations for this technology include:

• Difficult to detect smaller objects – The longer wavelengths cause data associated with very small objects to be distorted or incomplete.
• Less accurate measurements – The distortions created by these long wavelengths prevent you from receiving precise measurements of distance and the object’s other characteristics.
• Unable to distinguish between multiple targets – Radar technology delivers data on multiple objects at once. However, with the broad beam of the longer wavelength, it is unable to distinguish between multiple targets that are located close together, further limiting the accuracy of your data.
• Slower to lock on an object – Radar travels at a slower speed. As a result, more time is necessary to lock onto an object and deliver the data back to the device.

While these are significant drawbacks to using radar with speed enforcement applications, there can be benefits to this technology. With a longer wavelength, radar energy can better penetrate rain, fog and snow. We see how this works in the weather reports. It can deliver better results in these conditions if the operator can visually identify the target.

What Is Lidar?

Laser Tech’s (LTI) family of laser measurement devices are based on lidar technology. Lidar is an acronym which stands for Light Detection and Ranging. With lidar technology, transmitted discrete pulses of laser light are used to calculate the distance between the lidar device and an object being measured. Lidar devices can transmit laser pulses at a rate up to 25,000 pulses per second. These high pulse rates increase the number of measurement samples collected. This additional data increases the accuracy of the measurement while maintaining a measurement time that is less than one second.

Lidar’s sensitivity to signal reflections when coupled with precision timing circuitry, provides a variety of benefits:

• Extremely precise speed and distance measurements – The rapid laser pulses used by lidar technology travel at the speed of light (186,000 miles per second), increasing the accuracy of measurements. This allows for accurate speed and distance measurements of an object.
• 3D images – Achieve high resolution 3D images of an object at any surface, making lidar a popular solution for mapping and topographical applications.
• Highly accurate data – Lidar’s speed and short wavelength provide the ability to target specific objects, improving the accuracy of data obtained.
• Data is collected quickly – Because it is faster and more accurate than radar, lidar is an ideal solution for high capacity and data intensive applications. In large-scale applications, this technology proves itself a powerful and highly efficient resource.
• Integrates with other data sources – You can integrate lidar data with GPS data to more effectively map and calculate distances. This integration is used in conjunction with forest mapping and other remote sensing technologies.

Industry Leading Lidar Technology

Laser Tech developed the first police lidar speed enforcement unit in 1989. The accuracy and versatility associated with lidar makes this technology ideal for use in handheld speed guns. The LTI 20/20 Marksman provided the first time that law enforcement officers were able to aim through a scope, select the specific vehicle they wanted to target, and achieve highly accurate speed measurements. Since then, Laser Tech has remained on the forefront of lidar technology. With over 35 years of experience, we are industry leaders in speed enforcement devices.

Laser Tech’s handheld lidar speed guns provide you with a variety of benefits, including:

• Industry-leading accuracy
• More type approvals and enforceable court precedents than any other device
• Field tested, durable, rugged and weather resistant technology
• Custom-configured systems that address your specific needs
• Intuitive, easy to use operator interface
• Easily integrates with other smart technology

More About Laser Tech Measurements

• How LTI Lasers Work
• Measuring Height
• Laser Measure Horizontal Angles
• Laser Measure Level
• Laser Measure Speed