In today's world, the importance of data, information and knowledge should not be ignored.  Information superiority leads to decision making superiority and more effective actions. Within the military domain, various information systems are utilized to support commanders and troops to be aware and take control of the situation. Location information is one of the important aspects of the military information systems to provide situation awareness. Regarding the extensive applications oflocation-based military information systems, it is important to improve intelligence, knowledge base and integration of such systems. One of the current challenges in military information systems is that the applied systems are used as separate islands with no common protocol and language. In addition, computerized systems do not take the meaning of transferred terms and concepts into considerations. In other words, computerized military systems are not capable of establishing a meaningful relation at a conceptual level with each otherand also with humans. Moreover, data bases with different formats and data structures are not using similar method for modelling and storage of information and therefore, work as independent information silos. Furthermore, people knowledge is not coded and rarely modelled for future re-utilization. In this regard, one of the modelling methods is ontology that seems to be more effective than other methods. Ontologies provide an explicit and official description of common conceptualization. It implies that ontologies represent whatever exists in one information domain as concepts, relations, properties, rules and actual examples. In order to represent those concepts, ontologies employ a standardized and computerized official language. Common conceptualization inontology means that the produced concepts should be accepted by knowledge community of the interest domain so that the ontology becomes capable of providing a common language amongst people within the same domain such as military geography. Due to the importance ofthe location element, there is a need to develop specific geographical ontology to be able to use for such applications. A review of existing ontologies reveals that there are problems and challenges to employ available ontologies for military applications. For instance, some of the existing ontologies are only a hierarchy of concepts that cannot be called ontology to fulfill military requirements. Moreover, some ontologies are limited for specific geographical domains and others do not have complete coverage of geographical concepts which is required in military systems. In general, there is a need for geographical knowledge engineering and a localized geographical ontology development. Such ontology should contain geographical concepts, properties and relations with a military approach to be used in location-based military systems. In fact, development of geographical ontology provides official common language and standardization in the domain of military geography. In addition, it helps to model geographical knowledge and establish a conceptual infrastructure for location-based systems. Consequently, various geographical ontology-based systems can be developed with vertical and horizontal integration. Such ontology-based systems eliminate the problem of isolated data and information storage in separate islands, prevent missing data sources and support re-utilization of knowledge sources. Moreover, such geographical ontology-based systems can interact with each other and with humans in a higher meaningful conceptual level. In order to develop such ontology-based system, a semi-automatic method is utilized for knowledge engineering and ontology development. Applied method is a result of analyzing different methods to remove deficiencies in early stages of theontology development. Thus, a set of best applicable methods for geographical knowledge engineering is utilized for ontology development. Main clusters of geographical existence, geographical process and geographical properties are defined in the developedgeographical ontology. Other clusters of concepts include causing factor, military concepts, time concepts, situation concepts and general status related concepts. The developed ontology includes 4161 geographical concepts, 319 concept properties, 426 relations amongst concepts and 5527 actual examples of modelled geographical concepts using the proposed ontology.
In this research, the developed geographical ontology is using web protégéopen source software. The web-based version of the software enable easy access to developed environment from different locations while enables team work implementation in such a way that different people or groups of experts can access to ontology development and share thoughts and tasks. Moreover, it is possible to track changes, monitor and supervise the development process. It is also possible to program the ontology using the OWL standard language to be used in other systems. In general, the developed geographical ontology is capable of being applied in military location-based systems while it can also be deployed as support for other military and security ontologies. Finally, in order to assess quality, credibility and coverage of the developed ontology is examined and verified using a comprehensive mix of statistical, automatic and military geography expert opinions.