Swim study of the detectability of internal solitary waves

SWIM is a wave spectrometer on board CFOSAT designed to measure the wave spectrum over a width of 180 km [1]. In this paper, the ability of SWIM to detect ISWs is explored for the first time using SWIM data to investigate the internal isolated waves (ISWs) in the Sulu Sea. As an example, two identical ISWs are detected by the 8 degrees and 10 degrees incidence angle beams, and the empirical mode decomposition (EMD) method is used to separate and extract the ISWs signal from the echo power of SWIM and match the extracted signal with the ISWs; the SWIM data are detrended and moving average processed to calculate the perturbation changes of the SWIM echo signal caused by ISWs. The qualitative analysis shows that ISWs cause a perturbation in the SWIM echo power and that SWIM has the ability to detect ISWs. A preliminary comparison shows that the magnitude of the SWIM echo power variation is related to the characteristics of the ISWs themselves and the magnitude of the energy contained in the beam when the ISWs are detected.