This work mainly deal with the processing of Remote Sensed Images gathered from a radiometer flown aboard an environmental satellite. In this work some NOAA/AVHRR images have been used with focus on the southern Europe and the Mediterranean Basin. The images are navigated by resolving the satellite motion and the senors's scanning laws. And calibrated in order to obtain true radiance or temperature values. The first and second band of the AVHRR Radiometer are useful to distinguish between land and sea pixels. While the two thermal infrared channels (4 and 5) proved to be useful to find out the cloud affected pixels and to estimate the value of Sea Surface Temperature on the cloud free pixels. The presented method has been tested on an Intel Pentium 200 MHz based computer. It took 91 sec to perform the following steps: (1) Classify each pixel in one of the following categories: land, sea, cloud, cloud edge, coast line, outside the swath. (2) Estimate on sea, cloudy-free, pixels the Sea Surface Temperature by the means of a low noise split window algorithm on a multispectral image. This performance allows this estimation to be done in real time.