海洋—声学耦合过程不确定性快速预报
The rapid uncertainty prediction of the ocean-acoustic coupled model
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摘要: 针对海洋声速空间非均匀和时变条件下的声场不确定性快速预报问题,根据海洋-声学耦合模式预报声速场时空变化过程,获取声速垂直结构不确定性分布规律,提出经验正交函数-随机多项式展开方法,以降低不确定参数维度,得到声场不确定性分布.数值计算表明该方法在保证同等精度的同时可大幅减少计算量,相比常规随机多项式展开方法计算效率可提高2个数量级,且计算量不随声速剖面复杂程度变化而改变.经海上实验验证,结果表明该方法可实现环境不确定性条件下的声场及其不确定性的快速预报。Abstract: Focusing on rapid prediction of acoustic field uncertainty in environment with temporal and spatial sound speed perturbation, evolvement of sound speed structure over time is predicted based on the ocean-acoustic coupled model to obtain the uncertainty distribution, and a method based on non-instructive polynomail chaos expansion combined with empirical orthogonal function is proposed to reduce the dimensionality of uncertain parameters and to obtain the probability density function of acoustic field. Simulations prove that this method reduces the calculation guantity by 2 order of magnitude compared with regular polynomail chaos expansion with same precision. In addtion, the calculation guantity doesn't rise with the complexity of the sound speed structure. Experimental data shows acoustic fields and uncertainty estimation can be predicted with uncertain environmental parameters.