Water level and wave height estimates at NOAA tide stations from acoustic and microwave sensors

"The National Oceanic and Atmospheric Administration (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) is transitioning the primary water level sensor at the majority of tide stations in the National Water Level Observation Network (NWLON) from an acoustic ranging system to a microwave radar system. The primary motivation for this transition is the significant reduction in infrastructure and maintenance costs associated with the microwave sensor, which in ice-free conditions requires no contact with the water surface. The acoustic system requires a protective well that extends from above the highest water level to below the lowest water level and system maintenance requires disassembly, cleaning and dive operations. Installation of a new acoustic system requires nontrivial infrastructure to support the protective well. To assess the relative performance of these two sensor systems, CO-OPS initiated a program to compare performance of the acoustic and microwave systems at operational NWLON stations finding statistically equivalent performance at sites with little or no wave energy. At sites with wave energy (expressed in the standard deviation statistic of the water level estimate) a persistent bias was noted with acoustic water level estimates lower than that of the microwave sensor. This report is the culmination of a study to identify and assess these differences"--Executive Summary. Joseph Park, Robert Heitsenrether, William V. Sweet. "June 2014." System requirements: Adobe Acrobat Reader. Includes bibliographical references (pages 21-23). 2014 NOS (National Ocean Service) CO-OPS (Center for Operational Oceanographic Products & Services) Library Public Domain 1936