Remote sensing of sea surface features by optical RTI images

It is known that development of new remote sensing technique for investigation of sea surface features is an important oceanographic problem. This paper is focused on a new method of analysis of optical range – time – intensity images (RTI images) of sea surface [1-3]. The RTI image constructed from optical profiles of sea surface is an optical analog of a side-looking radar image of sea surface but having higher spatial resolution and some possibility for remote sensing of sea roughness. It is possible to form RTI images with range from some tens meters to tens kilometers depending on spatial resolution needed. A set of original optical devices for recoding RTI images using linear arrays of CCD-photodiodes was created [4-6]. The long surface wave fields, breaking of waves, near surface wind field features, eddies, wind fronts, catabatic winds, ship wakes, oil slicks, manifestations of internal waves on sea surface were recorded and investigated by this apparatus in inland waters and in the ocean [5-7]. Description of optical system, some new examples of RTI images of sea surface and its analysis are presented in this work. The principles of remote sensing of near surface winds by its manifestations on the water surface under grazing angles were developed. The model of RTI imagery of the water surface based on the expansion of image intensity on wave slopes and taking into account wave shadowing has been developed. The analytical dependence of intensity of water surface on wave slope dispersion permitting to restore velocity of near surface wind was received.