NOAA’s recent field testing of current and wave measurement systems – part ii

Abstract

The National Oceanic and Atmospheric Administration's (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) currently maintains twenty-two operational Physical Oceanographic Real-Time System (PORTS®) observatories throughout the United States' coastal regions. Ocean current observations are among the multiple PORTS® data products that provide critical support for safe navigation and a variety of scientific and engineering applications. To ensure that its observing network provides the most accurate and up-to-date products available, CO-OPS routinely conducts test and evaluation of newly available oceanographic sensors and measurement systems. From October 10 -December 3, 2014, CO-OPS conducted a field test in the South Chesapeake Bay which included three acoustic current profiling and wave sensors deployed in bottom mounted, upward looking configuration 1) the TRDI 500 kHz Sentinel V, 2) the Nortek 600 kHz AWAC-AST, and 3) the Nortek 500 kHz Signature 500 AD2CP; and an AXYS Technologies TriAXYS TM Next Wave II Directional Wave Buoy with Currents provided with an integrated Nortek 600 kHz Aquadopp acoustic sensor. Also included in the deployment was a bottom mounted TRDI 600 kHz Workhorse Sentinel acoustic current profiling sensor. The test site was near the mouth of the bay where currents are predominantly tidal and the average water depth is approximately 15 meters (50 feet). During the test, currents at the site ranged in magnitude from approximately 0-0.75 m/s on a daily basis and reached as high as 1.2 m/s (2.3 knots) on one occasion. Three high-wind storm events passed through the region and significant wave heights exceeded 2 m on multiple occasions. 978-1-4799-8419-0/15/$31.00 ©2015 IEEE

Evaluating Performance of Acoustic Current Profiler Sensor on Small, Dynamic Surface Buoy

“…During the 2018 test, once again, periods of shear were experienced at the test site, when northward velocity increases with depth. There were no large increases in the buoy mounted versus bottom mounted ADCP measurement deviations during periods of higher shear, as was seen in 2014 and 2015 field tests [2,3].…”

“…The sensor tested was a Nortek Signature1000 ADCP (1 MHz) with firmware modified to sample the AHRS output at the same rate as the acoustic ping rate, with precise synchronization. Based on previous test results [1][2][3], it was decided that initial testing of the new ADCP with AHRS would be with a basic, foam hull buoy. Test results are used to assess value of pursuing a following effort to integrate the enhanced ADCP with an actual wave measurement buoy (resulting in the same type of system used in previously reported tests).…”

“…However, previous work has shown that surface buoy-mounted ADCP current profile data can be negatively impacted by buoy motion in some dynamic, coastal environments. Between 2014 and 2018, a series of three field experiments were conducted to evaluate the performance of acoustic Doppler current profilers installed on small, dynamic surface buoy platforms (< 2 m diameter) at nearshore sites [1][2][3][4][5]. Results and conclusions from each experiment have led to successive modifications to the sensors employed, in an attempt to improve data quality for the system.…”

NOAA’s recent field testing of current and wave measurement systems – part i

“…The TriAXYS TM buoy also successfully measured continuous wave data over entire test. Wave measurements will be further discussed in a second paper, also included in these proceedings [9]. Continuous 6 minute winds were available from a nearby CO-OPS tide station Kiptopeke, VA (station number 863220).…”