English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Underwater source localization based on acoustic modeling has been a subject of intensive research since a long time. In the case of shallow water scenarios (which are characterized by multilayered bottoms) normal-mode based acoustic propagation models are often combined with Matched-Field Processing techniques in order to provide accurate estimates of both source range and depth. This work discusses the use of a ray tracing model for source localization. Accurate predictions of the acoustic field are obtained by replacing the multilayered bottom with an equivalent (single-layer) bottom, to be used by the ray model, where the properties of the equivalent bottom are obtained through parameter optimization based on the comparison between rays (single-layer) andmodes (multilayer) predictions. The accuracy of this approach is tested using data from an experiment performed by the former Undersea Research Centre of the Supreme Allied Commander Atlantic (SACLANT) in the north of the Elba Island, near the Italian coast. The results indicate that the proposed approach allows a ray model to locate an stationary source with the same accuracy as the one achieved with a normal mode model. Keywords: underwater acoustic modeling, ray-based models, normal mode models. RESUMO. A localizacao de fontes submarinas por meio de modelos de propagacao acustica e um antigo problema de grande interesse cientifico. Em cenarios de aguas rasas, que se caracterizam normalmente por fundos com complexos sistemas multicamadas, os modelos de propagacao baseados na teoria de modos normais sao geralmente combinados com tecnicas de Processamento por Campo Casado para produzirem estimativas acuradas da distância e profundidade de uma fonte acustica. O trabalho aqui apresentado propoe a utilizacao de um modelo de tracado de raios no problema da localizacao. De maneira a produzir estimativas acuradas do campo acustico, o modelo de raios recorre a um modelo equivalente do fundo, baseado numa escolha otima de parâmetros, os quais sao obtidos por meio da comparacao entre as previsoes geradas por um modelo de raios (que considera um ambiente de camada unica) e as geradas por um modelo de modos (que considera um ambiente original multicamadas). A acuracia da metodologia e verificada por meio de dados adquiridos ao norte da Ilha de Elba (nas proximidades da costa italiana), oriundos de um experimento realizado pelo entao Undersea Research Centre of the Supreme Allied Commander Atlantic (SACLANT). Os resultados alcancados indicam que a metodogia aqui proposta demonstra ser possivel um modelo de raios para localizar uma fonte estatica com acuracia comparavel aquela tradicionalmente obtida por um modelo de modos normais. Palavras-chave: modelagem acustica submarina, modelos de raios, modelos de modos normais.

USE OF RAY TRACING MODELING IN SHALLOW WATER ACOUSTIC SOURCE LOCALIZATION COMBINED WITH MATCHED-FIELD PROCESSING TECHNIQUES