TY - JOUR
AU - Boon, John D.
AB - A microwave water-level sensor, the Design Analysis model H-3611i, will soon enter service at tide stations operated by the National Oceanic and Atmospheric Administration’s Center for Operational Oceanographic Products and Services (CO-OPS) as part of the National Water Level Observation Network. CO-OPS tests include a multisensor deployment at the U.S. Army Corps of Engineers Field Research Facility at Duck, North Carolina, to evaluate microwave water-level measurement error over a wide range of Atlantic Ocean sea states. In situ precision and accuracy of processed (6-min average) water level is found to depend on sea state in addition to data processing methods and sensor operating mode. Estimates over selected 6-h measurement periods show that a degree-two polynomial successfully models the increase in sensor standard error with increasing zero-moment ( Hm 0 ) wave height but with differences in rate of error increase dependent on the application of a prefilter and choice of sensor operating mode. Prefiltering of 1-Hz “fast mode” sensor output to remove variance at selected wind-wave frequencies can reduce standard error during extreme conditions ( Hm 0 ≈ 3 m) from approximately ±3 cm without prefiltering to about ±1 cm using a least squares–designed (LSD) digital filter with a 60-s cutoff period. When wave heights are elevated, skewed non-Gaussian distributions develop within the 1-Hz (360 s) sample domain wherein a 3σ outlier elimination process applied without prefiltering can introduce a negative bias of up to 5 cm in individual 6-min water-level averages.
TI - Reducing Wave-Induced Microwave Water-Level Measurement Error with a Least Squares–Designed Digital Filter *
JO - Journal of Atmospheric and Oceanic Technology
DO - 10.1175/JTECH-D-13-00160.1
DA - 2013-07-26
UR - https://www.deepdyve.com/lp/american-meteorological-society/reducing-wave-induced-microwave-water-level-measurement-error-with-a-wYWJCF4J80
SP - 491
EP - 502
VL - 31
IS - 2
DP - DeepDyve
ER -