Last year, two hurricanes hit the state, causing widespread flooding on both coasts, and hitting Saint Augustine particularly hard. Now, with the 2017 hurricane season less than six weeks away, Florida’s emergency planners are already prepping the state’s response plan for potential storms. This year, emergency response agencies may have a new laser “weapon” at their disposal: Geiger-mode LiDAR (Light Detection and Ranging) manufactured by Melbourne, Florida-based Harris Corporation, to create precision elevation mapping that engineers and analysts can use to better predict how a storm might cause flooding in coastal regions of the state.
While the federal government has used Geiger-Mode LiDAR for the last twenty years, Florida has always relied on an older version of LiDAR to produce low-quality elevation data, and some parts of Florida have no elevation data at all.
LiDAR technology collects elevation data by sending and receiving pulses of light from airplanes, ground vehicles, or stationary devices and coordinating that data with GPS (Global Positioning System) satellites and IMU (Inertial Measurement Unit) which calculates the pitch, roll, and heading of the airplane or other LiDAR source.
Geiger-Mode LiDAR collects a higher quantity of more accurate data than typical linear LiDAR by flying at a higher altitude (25,000 ft vs 5,000 ft), firing multiple pulses from multiple angles, and collecting data from a larger array. The difference is a more accurate representation of the elevation of the ground, foliage, bodies of water, and buildings. Older forms of LiDAR collection have the potential to yield incomplete data in the form of voids, areas where the pulse were unable to penetrate, which result in a kind of “hole” on the elevation data map.
In a heavy rain situation, because of Florida’s extremely low relative elevation, some areas of the state may experience frequent flooding, while others are only affected by severe storms. Geiger-mode LiDAR data can tell you whether areas that are outside of high-risk zones may also be at risk during certain events,” said Kevin Lombardo, spokesman for Harris Corporation.
Geiger-mode LiDAR data has also has the ability to provide advanced warning to mitigate risks, warn population centers, and deploy assets for rescue.