FMCW LiDAR Range Calculator | Beat Frequency & Chirp Formula

This document explains how to calculate the distance to a target using FMCW LiDAR technology based on the beat frequency generated by the reflected signal. It provides the relevant equation and a calculator for determining distance.

FMCW LiDAR Distance Calculator-1

Inputs

Outputs

Use the calculator to determine FMCW LiDAR distance based on beat frequency, sweep time and bandwidth.

Example:

Input:

  • Beat Frequency (MHz): 10
  • Chirp Slope (MHz/μs): 20

Output:

  • FMCW Range in meters: 75

Constants:

  • Speed of Light (c): 3 x 10^8 m/s

FMCW LiDAR Distance Formula-1

FMCW LiDAR Distance Formula

FMCW LiDAR Distance Calculator-2

Inputs

Outputs

Example:

Input:

  • Fup = 12 MHz
  • Fdown = 8 MHz
  • S = 20 MHz/μs
  • Waveform Duration (T) = 1550 nm

Output:

  • FMCW Range in meters: 15
  • FMCW Velocity in m/s: 7.75 m/s

Constants:

  • Speed of Light (c): 3 x 10^8 m/s

FMCW LiDAR Distance Formula-2

Advanced FMCW LiDAR Distance & Velocity Formula

Applications/Benefits of FMCW LiDAR

  • FMCW LiDAR provides high precision range measurements, ideal for autonomous vehicles and robotics.
  • It can measure both distance and velocity, enabling advanced object tracking and collision avoidance.
  • FMCW LiDAR is less susceptible to interference from ambient light, improving performance in challenging environments.
  • The continuous wave nature of FMCW allows for longer detection ranges compared to pulsed LiDAR systems.
  • FMCW LiDAR can operate at lower power levels, enhancing safety and reducing energy consumption in applications like drones and mobile robots.

References for further study

  • Skolnik - Radar Handbook (FMCW principles)
  • LiDAR textbooks and research papers on FMCW technology
  • Velodyne and Ouster FMCW LiDAR product documentation