Advanced Digital Signal Processing for Hybrid Lidar
Abstract
Hybrid lidar-radar ranging systems experience two main challenges from operating in the underwater channel that degrade system performance, as shown in Figure 1. The first of these is absorption, which occurs when a photon emitted from the laser is absorbed by water molecules or dissolved materials. Absorption causes the received signal level to decrease. The use of blue wavelengths in open ocean or green wavelengths in coastal ocean can be used to minimize absorption. The second challenge occurs due to scattering, in which photons are deflected out from the collimated laser beam after colliding with particles in the channel. Scattering degrades resolution and reduces range accuracy. In addition, if a sufficiently large amount of photons scattered back into the receiver field of view, this can cause the system to erroneously detect an "object" at the center of the scattering distribution rather than detecting the desired object. Scattering has typically been mitigated by applying high modulation frequencies to the laser, as backscatter has been shown to have a lowpass frequency response [1,2],
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 2014
- Accession Number
- ADA619071
Entities
People
- William D. Jemison
Organizations
- Clarkson University