Internal time and phase synchronization for distributed micro-satellite SAR

Tight synchronization among micro-satellites is one of key technical requirement for distributed microsatellite SAR (DMS). Currently, time and phase synchronization solutions are considered separately. This paper first discusses influence of SAR caused by time and phase skew, and dictates requirements of synchronization for DMS. Then an integrative solution of time and phase synchronization is proposed with phase lock loop (PLL) and two-way time transfer. Based on micro-satellite architecture, the solution chooses to design individual transceiver, and implements time synchronization of the onboard computer (OBC) instead of effective load Radar transceiver, which will facilitate the implementation of global command and data handling (C&DR) system schedules for DMS. Its internal synchronization characteristic also guarantees autonomy and robust of synchronization of DMS.