Small Satellite Formation Flying for Distributed Synthetic Aperture Radar

Distributed Synthetic Aperture Radar (DSAR) is defined as a SAR in which the signal emitted by the transmitter and scattered from the area of interest is not collected by a single receiver but by many, conveniently distributed, formation flying, receivers. The concept of distributed aperture can enable new SAR working modes, but more important, thanks to passive operations, can achieve very high performance through a series of very compact, low weight, agile, satellite platforms. Such a distributed space system can be regarded as a system in which the payload functionality is broken apart and distributed among the different elements of the system. While fractionation and formation flying may lead to many advantages, distributed space systems pose a number of technological and operational issues at system and subsystem level. This paper focuses on basic system requirements and formation flying aspects relevant to DSAR. In particular, trajectory design approaches that can fulfil payload requirements while relaxing formation control issues are addressed. Long term stability is also investigated.