Spaceborne radar design equations and concepts

Spaceborne radar systems (SBR) can be designed for several modes of operation including airborne moving target indication (AMTI), ground moving target indication (GMTI), and synthetic aperture radar (SAR) mapping. Each application imposes a different design constraint, in addition to the nominal power-aperture requirements. AMTI and GMTI modes include consideration of such requirements as area coverage and minimum detectable velocity (MDV). SAR mapping mode design includes ground coverage, as well as ground resolution requirements. System requirement compromises may be necessary if a single radar is designed to operate in different modes. To this end, a cellular radar concept will be described where the antenna generates multiple beams, with each beam illuminating a specific search area, called a cell. This cellular approach will also extend the AMTI coverage.