标题： 用于实时提取源系数的DART浮标数据去潮汐处理，以进行业务化海啸预报 显示英文标题

标题： Detiding DART buoy data for real-time extraction of source coefficients for operational tsunami forecasting

摘要： 美国海啸预警中心使用从太平洋和大西洋海洋中部署的浮标网络传输的实时底部压力（BP）数据，以调整海啸预测模型的源系数。 为了获得准确的系数和因此获得的预测，必须考虑浮标处的潮汐。 在本研究中，比较了五种系数估计方法，每种方法处理潮汐的方式不同。 前三种方法基于（1）一个局部调和分析，涉及海啸事件发生前立即的29天数据，（2）每个浮标特定的68个预存在的调和成分，以及（3）对前25小时数据进行经验正交函数拟合，减去一个潮汐预测。 方法（4）是一种使用方法（1）作为输入的卡尔曼平滑器。 这四种方法在去潮后估计源系数。 方法（5）同时使用一个两分量调和模型来估计系数，该模型考虑了潮汐。 这五种方法使用来自十一座DART浮标的存档数据进行评估，并在其中叠加选定的人工海啸信号。 这些浮标代表了太平洋和大西洋中观察到的完整范围的潮汐条件和背景BP噪声，而人工信号具有各种模式并引起不同的信噪比。 使用不同数量数据的源系数最小二乘估计的均方根误差（RMSE）来比较这五种去潮方法。 在去潮方法之间，RMSE的变化超过两个数量级，通常按列出的顺序减少，其中方法（5）产生最准确的源系数估计。 通过等待海啸信号的第一个完整波到达，RMSE显著减少。 作为案例研究，使用记录的2011年日本灾难性海啸的数据比较了这五种方法。 显示英文摘要

摘要： U.S. Tsunami Warning Centers use real-time bottom pressure (BP) data transmitted from a network of buoys deployed in the Pacific and Atlantic Oceans to tune source coefficients of tsunami forecast models. For accurate coefficients and therefore forecasts, tides at the buoys must be accounted for. In this study, five methods for coefficient estimation are compared, each of which accounts for tides differently. The first three subtract off a tidal prediction based on (1) a localized harmonic analysis involving 29 days of data immediately preceding the tsunami event, (2) 68 pre-existing harmonic constituents specific to each buoy, and (3) an empirical orthogonal function fit to the previous 25 hrs of data. Method (4) is a Kalman smoother that uses method (1) as its input. These four methods estimate source coefficients after detiding. Method (5) estimates the coefficients simultaneously with a two-component harmonic model that accounts for the tides. The five methods are evaluated using archived data from eleven DART buoys, to which selected artificial tsunami signals are superimposed. These buoys represent a full range of observed tidal conditions and background BP noise in the Pacific and Atlantic, and the artificial signals have a variety of patterns and induce varying signal-to-noise ratios. The root-mean-square errors (RMSEs) of least squares estimates of sources coefficients using varying amounts of data are used to compare the five detiding methods. The RMSE varies over two orders of magnitude between detiding methods, generally decreasing in the order listed, with method (5) yielding the most accurate estimate of source coefficient. The RMSE is substantially reduced by waiting for the first full wave of the tsunami signal to arrive. As a case study, the five method are compared using data recorded from the devastating 2011 Japan tsunami.