Small satellites for sea surface sounding

The paper presents a method of processing signals of radar sensing of the underlying surface using illumination from existing spacecraft (navigation, communication) and a constellation of small receiving spacecraft using synthetic aperture antennas. Methods and Results. Small spacecraft have many advantages over large satellites. Thus, they are relatively inexpensive to build, take minimal time from design to launch, can be easily modified to solve a particular problem, and create less radio interference. The approach under consideration consists in redistribution of tasks to be solved between the constellation of satellites in orbit. Both regular high-orbit communication satellites and low-orbit satellite communication systems, as well as navigation satellites are represented as transmitter carriers (underlying surface illumination). These space systems use the necessary broadband signal. Receivers of reflected signals are placed onboard small spacecrafts, and one of the tasks of the system is to perform research experiments, including on-line monitoring of fast-moving atmospheric cyclones. The work applies the method of sea surface radar imaging based on reflected signal models. The main results of the research are as follows: (1) possibility to use as a probing signal both a pulse and a broadband signal with a priori unknown modulation law, (2) acceptable resolution, (3) possibility to significantly reduce the system cost as compared to the existing space radars of sea surface survey. Conclusions. As a result of using a multiposition radar system, which uses small receiving antennas with synthetic aperture and sea surface illumination from operating spacecraft, it is possible to move to a qualitatively new level of solving problems of sea surface remote sensing with spatial resolution up to 1 meter, regardless of illumination and cloud cover presence.