Restriction Analysis of SAR Azimuth Resolution Based on Cubic Phase Error

Based on quadratic Taylor series approximation, the restriction on SAR azimuth resolution owing to cubic phase error is deeply analyzed in this paper. To avoid the shortcoming of the non-orthogonality of Taylor series expansion adopted by the traditional analysis method, a new analysis method is proposed based on the Legendre orthogonal polynomial expansion in this paper. Accordingly, the restriction on azimuth resolution is deduced via closed expressions based on SAR systematic parameters. Finally, by using the simulation results of airborne and spaceborne SAR, it is shown that the proposed analysis method is effective and applicable in SAR systematic optimization and design.