Multistatic Radar Systems

Abstract

This chapter discusses the key elements in the design of a distributed multistatic synthetic aperture radar mission. A number of application domains are discussed, with an emphasis on single- and multi-baseline interferometric techniques, deriving lower and upper bounds to the required spacecraft separation. Several multistatic formation concepts (Cartwheel, Helix, etc.) are discussed within the general framework provided by the Clohessy-Wiltshire equations. Several canonical multistatic acquisition modes (bistatic, alternate bistatic, etc.) are introduced, and the particularities of standard SAR modes in a distributed mission scenario are discussed. Here, the drawbacks of burst-modes such as ScanSAR or TOPS in a multistatic configuration are highlighted. Relevant theory with regard to oscillator phase noise is introduced and followed by a discussion of several phase synchronization approaches. These include TanDEM-X like synchronization links, which are the preferred option for most high frequency mission concepts, and GNSS or data driven approaches, which may be adequate for less demanding or for lower frequency systems. At the end of the chapter, three novel proposed missions are discussed: the high-end Tandem-L mission; SIGNAL, a compact Ka-band mission; and PICOSAR, a C-band low cost passive add-on mission concept.