Efficient time-varying propagation modeling in range-dependent ocean environments using ray-bundle interpolation

Computationally efficient simulation of time-varying underwater acoustic channels is challenging because dense snapshot ray tracing is computationally expensive, particularly in range-dependent environments where eigenray families can change discontinuously. We propose a ray-history interpolation method with path-family consistency to address this challenge. The method first computes eigenrays at sparse time snapshots and clusters them using a history descriptor. Within each cluster, delay, amplitude, and phase are interpolated to reconstruct intermediate impulse responses and synthesize received signals at intermediate times. In simulations with moving sources and receivers, the proposed method achieves correlation coefficients above 0.95 relative to dense snapshot references, while reducing total computation time by approximately 70%. These results indicate that the proposed method provides a practical approach for time-varying channel modeling under realistic computational constraints.