Challenges facing ocean remote sensing are as unlimited as the variety of sea surface dynamics and meteorological conditions across the globe and their range of spatial and time scales. Ultimate goals are to be able to make accurate estimates of selected key sets of geophysical variables, with the intention of either making predictions across time and spatial boundaries, or advancing fundamental knowledge through development of empirical relationships and/or theoretical models. Improvements are constantly being sought in both our understanding of the geophysical processes themselves, the sensor physics and the electromagnetic and microwave properties of the surface and its associated airsea interface, as well as the sampling capabilities to ensure proper monitoring using the vast number of specialized technologies that can be selected to concentrate on one or a few of the physical processes for accurate measurements. The increasing quality, quantity and duration of these ocean observations are then critically important for practical applications as well as to assess local or global climate changes, both from natural and manmade influences.