Research On Semantic Analysis And Formal Expression Of Marine Flow Field Based On Ontology Theory

The construction of spatio-temporal data organization model of marine flow field is one of the forefront research topics of marine GIS.The purpose of its construction is to achieve an objective description of marine flow field and reveal the rich information contained in the flow field.Due to the complex characteristics of the marine flow field,there are many difficulties in the semantic organization and consistency expression of the ocean flow field.At the same time,with the development of scientific research and the advancement of detection technology,the ocean flow field data has become more abundant.The flow field data with a geometric progression has different sources and diverse structures,which also poses challenges for the spatial and temporal data organization of marine flow fields.Therefore,how to solve the problem of heterogeneity in the representation of the phenomena and the data structure of the ocean flow field and reflect the ocean flow field in a more original way is one of the important research directions of marine GIS.This paper aims at the semantic heterogeneity of ocean flow field,and realizes the semantic analysis of ocean flow field based on ontology theory in the process of constructing ocean flow field phenomena and ocean flow data ontology.The OWL ontology description language is used to realize the formal expression of the ocean flow field semantics.Through the research on the current classification system of ocean current phenomena and the classification system of ocean current data,the basic characteristics of marine flow fields are summarized and pointed out..The paper concludes that the ocean current phenomenon has typical dynamic characteristics,spatio-temporal distribution characteristics,boundary ambiguity,etc.It also points out that there are multi-scale and multi-structure characteristics in marine flow data.According to the existing classification system,this paper divides the concept of marine flow field into basic object concept,attribute feature concept,relation concept and so on.It is especially aimed at the conception of ocean current phenomenon.This paper uses the theory of formal ontology to realize the classification of ocean current phenomena.In the analysis of ocean current phenomena and ocean current data ontology,the seven-character ocean current phenomenon ontology structure and the five-member ocean current data ontology structure are proposed in accordance with the characteristics of domain knowledge.At the end of the paper,based on the theory of topology and ontology,the definition and formal expression of the relationship between the spatio-temporal process of ocean currents are presented.The semantic analysis method of ocean flow field based on Ontology realizes the formal expression of concept,attribute and relation of ocean current,and makes it possible to share the ocean flow field data.The powerful knowledge analysis ability of the ontology and the efficient semantic expression ability of OWL provide powerful theoretical and technical support for the knowledge representation of ocean flow field.The semantic description system and the structure model of the ocean flow field have shown that the semantic analysis method of the ocean flow field based on the ontology can effectively describe and organize the semantic information of the ocean flow field,and provides a reference for the study of the semantic expression research of the ocean information.