This chapter reviews the methodology, sampling capabilities, accuracy, and applicability of the techniques and provides an overview of the processing stages required to extract useful measurements from the raw digital data recieved from the satellite. It also reviews how such measurements have been applied by numerical modelers of marine systems. The chapter examines in more detail a case study of an attempt to drive a model with remotely sensed data, a spatially detailed two-dimensional model of thermal structure in a vertically mixed shallow sea. It considers the problems of using models to interpolate in time between image data which are only occasionally sampled. The chapter discusses the new possibilities for improved model parametrizations which can now be used to exploit the spatially dense data from remote sensing. It also considers the types of measurement which can be made using different remote sensing methodologies and the space-time sampling capabilities of satellite scanners.