Persistent Wide-Area Maritime Surveillance Using Smallsats With MIMO Radar Beamforming

This article presents an application, using existing technology, that would implement persistent (uninterrupted) noncooperating maritime surveillance of ship targets over wide areas of the Earth's surface. Persistence is essential for detecting and monitoring fleeting events, such as piracy, cargo transfers at sea, human migrations, and ship capsizings. The application would employ active radars aboard a constellation of small satellites (smallsats) placed in geostationary orbit. It would be augmented with the employment of existing multiple-input–multiple-output beamforming technology in order to reduce, to practical levels, the number of smallsats needed. An example is presented in which such a constellation would provide L-band surveillance of seas adjoining southern Europe, including the Mediterranean, Adriatic, Aegean, and Black Seas. An investigation of ship detection in the presence of sea clutter is included. The major design challenges are assessed to include the minimization of aggregate payload launch mass and the minimization of the data processing burden. In addition, comparisons are made with alternative approaches. Finally, in view of the large scale of such a prospective deployment, a risk reduction plan is offered, along with suggestions for design variations.