Abstract: Along-Track Interferometric Synthetic Aperture Radar (ATI-SAR) has the potential to measure the radial velocities of slowly moving targets. The accuracy of the radial velocity is limited by the accuracy of the interferometric parameters. Sensitivity equations are good ways to analyze the impact of the system parameters on interferometric SAR. Available sensitivity analysis for ATI-SAR mainly focuses on the case of no squint angle. In this paper, the expression of the radial velocity in the presence of squint is derived firstly, and the sensitivity equations are further obtained. Moreover, the sensitivity of the interferometric parameters is simulated with airborne parameters, and the accuracy requirements for different parameters are given for different velocity accuracy requirements, which provide quantitative reference for real airborne ATI-SAR analysis and calibration requirement analysis.