A Line-scanning, Low-Cost LiDAR System for Continuous Beach Morphology Observations

Abstract:

Coastal communities face a growing threat of flood hazard due to sea level rise and more frequent and intense extreme events (e.g., hurricanes and nor’easters). Accurate and reliable predictions of coastal geomorphic change before, during, and after an event – all of which are directly related to flood risk – suffer from a dearth of high-resolution topo-bathy observations, and poor parameterization of the governing physics. Multiple federal agencies are leading a multi-agency effort to develop more robust models for better predictions of barrier island response and recovery to extreme events. Improvements in short- and long-term predictions require collecting comprehensive field data using remote sensing technologies. Recently, terrestrial LiDAR (Light Detection and Ranging) has provided a practical means to obtain high spatio-temporal resolution measurements of coastal phenomena. However, turnkey LiDAR systems capable of performing coastal mapping and monitoring are highly cost-prohibitive for widespread adoption ($50,000 - $250,000+). This presentation will outline the recent efforts undertaken to develop a Line-scanning, Low-Cost (LLC) LiDAR coastal mapping system. The LLC LiDAR system combines a multitude of off-the-shelf, DIY electronics components that a typical robotic hobbyist may use, with custom mechanical and optical components. Communication between LiDAR units is achieved via a DHCP-enabled access point using a Raspberry Pi 3 B+ and MAC filtering. The low-cost feature is particularly important for monitoring coastline evolution during storm impact; many owners of expensive LiDAR outright refuse to deploy a $250,000 piece of equipment in the direct path of a landfalling hurricane. Benchmarks and performance evaluation results of the newly developed scanning systems will be presented.