Effects of Acceleration on Doppler rate-based Velocity Estimation Technique using Distributed SAR Sensors

In recent years, the miniaturization of space radar systems has been a key enabler for the deployment of Synthetic Aperture Radar (SAR) sensor constellations. This trend offers the potentiality to estimate kinematic parameters of moving targets exploiting the spatial diversity among platforms. In this context, a technique based on the exploitation of the relationship between velocity and residual Doppler rate has been developed in [9], with specific focus on maritime targets. However, since movers may present more complex motion, the technique's performance may be influenced by the presence of longitudinal accelerations. This study aims to analyse these effects, with particular emphasis on how increasing the coherent processing interval influences the sensitivity of velocity estimates to acceleration. To achieve this, the impact of acceleration is examined and the limits of applicability of the Doppler-rate-based velocity estimation technique are determined. Both simulated results and theoretical performance analyses are provided.