Resolution calculation and analysis in high-resolution spaceborne SAR

In high-resolution spaceborne synthetic aperture radar (SAR), the hyperbolic range equation assumption fails to precisely describe the range history; thus, the traditional resolution analysis used for a spaceborne SAR design is imprecise. A curved orbit geometrical model based on the modified equivalent squint range model is graphically presented by vector notation. According to the model, the vectorial calculation of resolution is analytically presented, based on the gradient method. Additionally, a physical model is introduced to derive the effective integration time, which is quite difficult to derive due to the three-dimensional curved orbit. Simulation results are presented to validate the proposed method.