The complete and continuous illumination of the oceans with signals from Global Navigation Satellite Systems (GNSS) has been used to investigate the capability of a Low Earth Orbit (LEO) mission scenario to measure surface characteristics over wide ocean areas. The concept is based on receiving and processing both the direct and ocean reflected signals from a certain number of satellites. A software simulator has been developed for an aircraft scenario. The basic magnitudes for a possible array antenna configuration in the case of the LEO satellite scenario have been derived. Finally, a validation of the theoretical results with data collected during field measurements over sea water from a bridge is presented.