What is LiDAR?
Light detection and ranging (LiDAR) techniques use lasers to create 3D (topographic) or gas concentration (atmospheric) imagery of the surveyed environment. Both uses for LiDAR can be performed using either pulses of laser light (pulsed lasers) or laser light that stays on all the time (continuous-wave lasers). Bridger Photonics makes use of continuous-wave LiDAR to measure both solid surfaces (hard targets) and gases (soft targets).
TOPOGRAPHIC LiDAR WITH CONTINUOUS-WAVE LASERS
Frequency-Modulated Continuous-Wave (FMCW) LiDAR
FMCW LiDAR uses the frequency (i.e. color) of the laser light to determine distance. This method enables the simultaneous measurement of distance and velocity, generating precise location data.
HOW IT WORKS
ATMOSPHERIC LiDAR WITH CONTINUOUS-WAVE LASERS
Continuous-Wave Laser Absorption LiDAR
A continuous-wave laser can be changed or modulated to achieve the same effect as differential absorption. This laser absorption spectroscopy technique is known in various forms as wavelength modulation spectroscopy (WMS), frequency modulation spectroscopy (FMS), or tunable diode laser spectroscopy (TDLAS). Bridger mounts the LiDAR systems on aircraft, so the ground serves as a scattering point of laser light back to the LiDAR system.
HOW IT WORKS
TOPOGRAPHIC LiDAR WITH PULSED LASERS
The simplest and most well-known form of LiDAR, direct-detect LiDAR refers to the use of pulsed lasers to determine distance to topography (i.e. solid objects) for 3D imaging.
How It Works
ATMOSPHERIC LiDAR WITH PULSED LASERS
Pulsed Differential Absorption LiDAR (DIAL)
Using the fact that each gas absorbs a specific frequency of laser light, pulsed DIAL can determine the concentration of a gas by comparing the returning light from a laser pulse that is absorbed by a gas to a laser pulse that is not absorbed by the gas.