Model amending of Marsh-Schulkin propagation loss in shallow sea based on field anomalies

Aiming at the problem that the traditional M-S propagation loss estimation model is insensitive to the loss of submarine and sea surface propagation, this paper presents a method to improve the sensitivity and accuracy of the submarine absorption parameters. According to the near-field anomaly of M-S, the upper and lower limit of geometric propagation is different. This paper gives a new extended calculation method. By calculating the near-field anomaly coefficients, the new computational model is further evaluated for any negative gradient, which is further calculated for the upper and lower slope terrain. The sea trial data show that the redefined M-S model estimation has higher accuracy and more sensitive computing power under the premise of guaranteeing fast computation.