This paper concentrates on accurate motion compensation method for airborne SAR in diving model.The equivalent squint range model is deduced in the case of constant acceleration movement and CA-ECS (Constant Acceleration-Extended Chirp Scaling) imaging algorithm is proposed with new phase compensation factors based on this range model.The influences of multi-directional velocities and accelerations are taken into account in phase compensation factors of CA-ECS algorithm

so motion compensation with acceleration can be achieved via phase compensation.This algorithm is a more versatile and applicable imaging algorithm for subaperture data.The computer simulation results illustrate that the squint range model has less error and CA-ECS algorithm can be used to accomplish motion compensation with acceleration efficiently.