# A Heterogeneous Battlefield Situation Information Sharing Method Based on Content
## 3 Entity Oriented General Description of Battlefield Situation Information
### Description and Organization of Internal Information about Entities Based on a Template  
The internal information about entities refers to the static information such as the category, attribute, and state of entities. For this information, we designed a general information description template based on the attribute concept-logic tree to realize the uniform description and organization of the heterogeneous information from different systems. When designing templates, two aspects should be paid attention to: (1) selecting the appropriate information description language to ensure the accuracy, sufficiency, and flexibility of information description; (2) selecting the appropriate template structure to ensure the consistency of the heterogeneous information description. As a widely used markup language currently, XML has the advantages of self-description, structure, and platform independence, as well as strong knowledge representation ability, semantic annotation ability, and extensibility. Therefore, we adopted XML as the description language in the design of the general information description templates, i.e., templates were constructed with XML and stored as XML documents. Considering that an XML document is formally represented as a tree structure after parsing, which has a good comparison relationship with the attribute concept-logic tree model, we adopted a tree structure to design the general information description templates. Besides, to ensure the integration correctness and efficiency of the presented information, when designing a template, the structure of the template was in strict accordance with the structure of the corresponding  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Rule** & **Expression** & & **Property** \\ \hline
1 & IF \(r_{a}\subseteq r_{b}\  
attribute concept-logic tree. That is, one-to-one correspondence between the nodes of the attribute conceptual logical tree and the nodes of the template parse tree existed. As showed in Figure 8, based on the general information description templates, the heterogeneous internal information about entities can be described, organized, and stored in a structured way; where the information organized is stored with XML documents that are entity oriented, i.e., the information of each entity is stored with a document separately. On this basis, operations such as information integration and acquisition can be transformed into the corresponding operations such as pruning, merging, or retrieval based on the information tree, which is easy to implement. Description and Organization of External Information about Entities Based on the Semantic Link Network  
Entity relationships are used to describe the relations between geographic targets, combat units, and concepts such as combat missions. Among them, the relations among geographic targets are stable and can be viewed as static within a somewhat long period. The relations between the combat unit and geographic target are relatively simple; they mainly describe the location and direction of combat units with respect to a particular geographic target in the combat area; while the relations among combat units are relatively complex, e.g., there are various relations exist, such as subordination, command, collaboration, guarantee, and so on. Since combat units possess complex attributes such as mobility, combat capability, and functionality, the relations among combat units are dynamic and mission related. For example, suppose \(e_{x}\), \(e_{y}\), and \(e_{z}\) represent three combat units that belong to different services, while they are executing the same mission at time \(t\). If \(e_{x}\) possesses the command authority, then \(e_{x}\xrightarrow{Command}e_{y}\), \(e_{x}\xrightarrow{Command}e_{z}\), and \(e_{z}\xrightarrow{Collaborate}e_{y}\) are satisfied at this time. However, after the mission is finished, these relationships may no longer be satisfied. Thus, the relationships among entities actually form a relational network that is dynamic, real time, and mission related.