Range‐Doppler‐Acceleration Estimation for Fast‐Moving and Accelerating Targets

ABSTRACT Fast‐moving and/or accelerating targets challenge conventional pulsed‐radar processing because the received echo may exhibit both pulse‐to‐pulse migration and intra‐pulse motion‐induced distortion. In such cases, standard range–Doppler processing based on stop‐and‐go or negligible intra‐pulse motion assumptions can suffer substantial loss of focus and estimation accuracy. This paper presents a generalised framework for range–Doppler–acceleration estimation that remains compatible with efficient FFT‐based processing while accounting for these effects. The approach is based on a Cruise‐and‐Go approximation, which linearises the target motion within each pulse, leading to both carrier frequency Doppler shift and baseband signal stretch, while allowing pulse‐to‐pulse variation. The resulting method is waveform independent and applicable to arbitrary frequency‐ and phase‐coded signals. Its performance is analysed in terms of estimation accuracy, computational complexity, and ambiguity behaviour, with comparisons to existing methods. A unified metric is introduced to predict correlation loss. Simulations show accurate refocusing and estimation performance close to the Cramér–Rao bound, making the method suitable for long‐pulse and wideband radar applications, including space surveillance.