Automatic Detection of Internal Waves on Satellite Images and Estimates of the Mixed Layer Density

Abstract

This work presents an automatic algorithm for detecting internal waves (IWs) using the visible channel images of the MODIS radiometer. The algorithm is based on the local Hough transform. The sources of detection errors and the possibility of excluding false detections are considered. If a train of IWs is detected, it is possible to estimate the wavenumber. The wavelength in the images used in our experiments is within the range 1300–2200 m. The speed of IWs is estimated using two adjacent passes of the Aqua and Terra satellites. The speed and wavenumber are used for estimating the density characteristics of the mixed layer in a two-layer model with constant density. The estimated density difference between the layers based on satellite data is in a good agreement with the in situ data.