Presentation outlining JOA Surveys’ online tidal datum computation tool.
A lack of coastal infrastructure in western Alaska poses a challenge to efforts directed at collecting water levels referenced to tidal datums for storm surge analysis. The two primary challenges are sensor stability and the level of effort required for sensor installation. JOA Surveys, LLC (JOA) developed a system to measure storm surge in low areas with existing deep rod style tidal benchmarks that can be deployed with no tools and the installation time is less than 10 minutes. JOA tested this system in Kinak Bay and successfully measured storm surge during a September 2016 storm. Follow link above to download pdf in a new window.
NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) has developed an innovative system design to collect water level data in remote cold climate regions where winter sea ice precludes traditional tide station installations. Barrow Alaska 2008-2010.
A Point of Beginning (POB) article my Mike Zieserl about tertiary tide stations in Kenai Fjords Alaska – May, 2001.
In August and September of 2009, David Evans & Associates (DEA) deployed a GPS buoy in Chesapeake Bay. JOA Surveys, LLC (JOA) used the 1Hz RT and PPK solutions to compute tidal datums for comparison with VDATUM through water level transfers from Lewisetta to the Buoy and a similar transfer from Windmill Point resulting in final datums within 2cm of the VDATUM determination at the location of the GPS buoy.
Under a charting contract with the National Oceanic and Atmospheric Administration (NOAA), David Evans and Associates, Inc. (DEA) was tasked to evaluate the VDatum model in addition to mapping large portions of Chesapeake Bay. Using a buoy outfitted with GNSS and a tilt sensor, tidal datums were computed at three locations bounding the project area in 2009 and 2010. Final results were compared with existing shore-based tide stations, GNSS water levels computed on two survey vessels and the VDatum model.
In 2008 a combination of National Water Level Observation Network (NWLON) tide stations, tertiary tide stations, submersible pressure sensors, and hydrographic vessels were used to measure and zone water levels in Alaska’s Cook Inlet. The goal during the 2008 field season was to apply the experience gained from surveys during the past decade to derive MLLW to NAD83 transformation parameters that can be used in future surveys.
Under a charting contract with the National Oceanic and Atmospheric Administration (NOAA), David Evans and Associates, Inc. (DEA) was tasked to evaluate the VDatum model in addition to mapping large portions of Chesapeake Bay. Using a buoy outfitted with GPS and a tilt sensor, tidal datums were computed at six locations distributed throughout the 2009 and 2010 project areas. JOA Surveys, LLC (JOA) computed tidal datums from the ellipsoid referenced water levels using the Tide-by-Tide (TBYT) method of simultaneous comparisons with NOAA’s permanent tide stations.