2.4 Requirement of the laser for altimetric LiDAR

 

Altimetric LiDAR primarily uses the range measured by the laser ranger.  To realise accurate and long range measurement the laser pulse should have the following characteristics:

         High power: So reflectance is available at receiver

         Short pulse length: Less uncertainty in time measurement

         High collimation: Less uncertainty due to smaller footprint

         Narrow optical spectrum: Small bandpass filter to reduce noise

         Eye safety: The lasers are more dangerous as wavelength reduces

         Spectral reflectivity of laser from terrain features: So reflectance (signal) is available.