Attributing Environmental Uncertainty Values to ALB Surveys

Firat Eren and Matthew Birkebak


Friday, Apr. 1, 2016, 3:00pm
Chase 130

Airborne Lidar Bathymetry (ALB) waveforms provide a time log for the interaction of the laser pulse with the environment (water surface, water column and seafloor) along its ray-path geometry. Using the water surface return and the bottom return, it is possible to calculate the water depth. In addition to bathymetry, the ALB bottom return can provide information on seafloor characteristics. In this study, the interaction of the ALB beam with the water surface and the bottom return was investigated. Data analysis and a system-agnostic approach were developed in order to distinguish between different environmental cases. We will present our work using an underwater detector array as part of the lidar simulator to demonstrate temporal and spatial beam diagnostics for analyzing green (532 nm) laser underwater-beam scattering and reflectance. The laboratory performance evaluation tests were conducted in the Ocean Engineering Tank Facilities at the University of New Hampshire. In addition, ALB survey data collected near the Merrimack River Embayment, Gulf of Maine, USA was used as a case study to characterize the bottom. The study results showed a good correlation to acoustic backscatter collected over the same area. 


Firat Eren received his Ph.D. degree in Mechanical Engineering from University of New Hampshire in 2015. During his Ph.D., he worked on development of optical detector arrays for navigation of unmanned underwater vehicles (UUVs). He got his M.S degree in Mechanical Engineering from University of New Hampshire in 2011 and his B.S degree in Mechatronics Engineering from Sabanci University, Istanbul, Turkey in 2008. He is currently working as a Postdoctoral Research Associate at the Center for Coastal and Ocean Mapping (CCOM). At CCOM, he is working on Airborne LIDAR Bathymetry (ALB) systems with a focus on characterization of the measurement uncertainties due to the environmental effects such as variations in water column and seafloor characteristics.

Matt Birkebak received a B.S. in mechanical engineering from UNH in 2015. During his undergraduate time, he participated in a summer SURF fellowship at CCOM in 2013. He worked on spectral restoration of underwater cameras under Drs. Shachak Pe’eri and Yuri Rzhanov. Through this experience, he became interested in ocean optics and bathymetric Lidar. Matt is currently pursuing his master's where he is looking at bathymetric Lidar uncertainty caused by ripples in the air-water interface.