This paper proposes a novel work mode of spaceborne ScanSAR with multiple azimuth beams

where the range swath coverage can be greatly extended while the azimuth high resolution remains unchanged.Based on the analysis of the characteristics and main phase errors of this mode

the compensating methods for these errors are given.Then the echo data simulating methods for this mode are introduced and the corresponding imaging algorithms are discussed as well.Thus the feasibility of this mode and the validity of the compensating methods are proved by simulation.