A fast echo simulation method for high-speed synthetic aperture sonar utilizing frequency-domain scaling transformation

Under high-speed conditions, the traditional stop-and-hop assumption is inadequate for accurately characterizing the temporal Doppler effect in synthetic aperture sonar (SAS) echoes, while existing time-domain high-speed simulation methods usually involve high computational costs. To address the computational inefficiency in high-speed SAS echo simulation, this paper proposes an efficient simulation method based on frequency-domain scaling properties. Building upon a high-speed echo model, the proposed approach solves for the signal spectrum in the fast-time domain and introduces scaling transformations to characterize the temporal Doppler effect induced by high-speed motion. As a result, scene echoes are directly generated in the frequency domain, effectively avoiding the excessive computational overhead of traditional methods. Simulation results show that, while maintaining accuracy comparable to time-domain methods, the proposed method reduces the simulation time of a single receiver by approximately 60%. Furthermore, in large-area scenes and multi-receiver system configurations, the proposed method effectively reduces simulation time, providing high-speed SAS systems with efficient echo data support.