A Simulation Method of HFSWR Tsunami Echo Based on COMCOT

High Frequency Surface Wave Radars (HFSWR) can obtain some very important sea surface dynamic parameters. When a tsunami occurs, the sea surface dynamic parameters will undergo certain changes. Based on this, HFSWR is also an important tool in tsunami observation and warning by detecting the changes of sea parameters, such as radial velocities of ocean currents. But tsunamis are relatively rare. Due to limited observational data, many correlational studies only can rely on simulations. So, it is essential to use a numerical model that calculates accurately the tsunami propagation from a source region to the coastal areas of concern. In previous simulations of tsunami flow velocities were based on the relationship between water depth and flow velocity, which was not precise enough. In this study, the COMCOT (Cornell Multi-grid Coupled Tsunami model) is used to simulate tsunamis in the desired region. COMCOT is capable of efficiently studying the entire life-span of a tsunami, including its generation, propagation, runup and inundation. And multiple tsunami-generating mechanisms can be implements in COMCOT. In COMCOT, both linear and nonlinear shallow water equations are available in spherical or Cartesian coordinate system for numerical studies at different scales. Using COMCOT can improve the accuracy of the simulation. Then COMCOT simulation results and the existing mature sea state remote sensing model are used to calculate the radar echo parameters of the tsunami, and the radar echo signal model of the tsunami in the region of interest is also obtained. Finally, the tsunami echo signals of the whole region are superimposed according to the spatial relationship to form the radar time domain echo data based on the uniform linear array. The method proposed in this paper can realize flexible tsunami modeling and radar configuration, analyze the spatial and temporal characteristics of HFSWR tsunami echoes in different scenarios, and can be used for the design of tsunami monitoring signal processing algorithms, monitoring and tracking performance evaluation, etc., which has a very important role in promoting the development of HFSWR tsunami monitoring technology.