Distributed Multi-Antenna SAR Antenna Synchronization
This chapter analyzes the impacts of antenna directing synchronization errors on distributed multi-antenna synthetic aperture radar (SAR)systems and introduces the beam scan-on-scan technique, followed by the pulse chasing. Besides time and phase synchronization, antenna synchronization is also required for distributed multi-antenna SAR systems. Due to the high difference between the velocities of the platforms, both systems must perform antenna steering to achieve an appropriate scene length in azimuth. Since SAR is a two-dimensional imaging technique, we analyze the impacts of antenna directing errors from range dimension and azimuth dimension separately. The step scan approach consists of fixing the transmitting beam position and scanning the receiving beam across the transmitting beam. The transmitting beam is then stepped one beamwidth and the receiving beam scan is repeated, and so forth until the transmitting beam has stepped across the surveillance sector.