Sea-viewing

Abstract. A coherent pattern of system noise observable on all visible wavebands of Landsat Thematic Mapper images over homogeneous surfaces such as waterbodies is regarded as serious enough to impair visual interpretation and affect image analysis results. The noise is removable using iterative median filtering in the spatial domain, which requires much less processing time than removal by frequency domain Fourier transform. The significance of the error introduced to the images by the noise is evaluated in terms of water quality parameters in the study area, and methods for removal of the noise are described. 1. Background Remote sensing of coastlines and small waterbodies is still dependent on sensors which have a low signal-to-noise ratio (SNR) over water since the high spatial resolution required for these areas, as opposed to the open ocean, is not available among the current high spectral resolution sensors calibrated for water, such a