Research On Standards System Of Geographic Information According With The Principle Of Share And Consistency

Servicing objects or phenomenon directly or indirectly related to locations on the earth, the major task of geographic information standardization is to work out a series of structured standards for defining, describing and managing geographic information according to standards of information technology. The past years witnessed great achievements in this research area, especially in modeling technology, technical standards of information sharing and interoperability, testing of standards' consistence, description of conceptual patterns, data standards, standards for applied services of geographic information, etc. These achievements significantly improve the standardization of applications in this field. However, for some essential problems, we still have no breakthrough research achievements. These problems affect the integrity of standard system and the definition of standard system's framework. For example, we lack research work on the concept of dependent contexts and logical structure of standard system. Few analyses have been done systematically on how to construct standard system and primary elements of standard. The class of standard aggregation dos not match dependent contexts. Aiming to helping solve these problems, this thesis applied theories of system engineering and principles of standardization to analyze technical standard system of geographic information. The analysis if this thesis focused on studying the structure of dependent contexts, primary elements of standards and principles of information sharing. By building models and conducting structural analysis, this thesis proposed a structural model for state-level technical standard system of geographic information. A structural framework of this standard system was built by engineering development approaches.Technical standard system of geographic information and the dependent contexts of this system are featured by the nature of a system. However, in the area of geographic information research, few works can be found to study standard system and dependent contexts by system engineering approaches. One of the innovations of this thesis is to root its research works of standard system and dependent contexts on the theory of system engineering and principles of standardization (Chapter 2 and 3). Especially in the analysis of standard system, a standpoint is proposed that to study and work out a standard is to find primary elements of the standard and add constraints to it. Hereafter this thesis sum up some primary elements of standard from ISO19100 serial standards and some related references, and studied them in detail. If these primary elements can be appropriately processed, obstacles generated from problems of standard system, which blocks information from sharing, can be eliminated. This will assure the implementation information sharing and interoperability.Dependent context system in general is a man-designed conceptual system while its constitutional parts are logically connected. Some of these constitutional parts are entity systems. The objective of studying dependent context system is to figure out its constitutional structure. So it is critical to identify and draw out fundamental entities that constitute this dependent context system. Previous research works on this point is not sufficient. This makes it groundless to decompose the structure of standard system. This thesis studied in depth the structure of overall framework of dependent context system as well as theoretical contexts, technical contexts and application contexts etc. Based on this analysis, the large numbers of constitutional elements are sum up to several classes of fundamental constitutional entities logically. These classes are research and design, data product technology, data and product, quality control, physical facilities, system and database, web and interoperability, data management and data security, application service, system documents etc. Objectivity and scientificity of fundamental entities' existence are also confirmed by analysis of the behaviors of dependent contexts. This result established the foundation of how to decompose and classify the structure of standard system.Chapter 4 of this thesis analyzed and >? principles of information sharing. Standard is the key that technically ensures the realization of geographic information sharing. Obstacles generated from problems of standards that blocks information from sharing must be eliminated. From the mode of sharing, we have the following types of sharing: metadata-based sharing, data format transformation, direct accessing mode, spatial data service, and interoperability of distributed web system. To realize these sharing methods, the key is still in the standard of sharing and interoperability.There are a lot of research achievements in metadata research. ISO defined a metadata conceptual model in its standards. However, the metadata model provided by ISO is only a schematic description and it is not possible to make clear the structure of metadata and its evolvement from this definition. Upon this understanding, chapter 4 of this thesis proposed a novel conceptual model for description of metadata. This model is capable in more accuracy and more detail to describe the metadata concept, collection and extension, as well as relationship between elements ofmetadata and high-level abstraction with its connection to metadata.Consistency of standards is to ensure the consistency of models, descriptions and constraints of the same object in different standards. There are a lot of methods and standards to test and determine consistency. However, it is very difficult in experience to establish correlations between standards in large-scale standard set. In order to solve this problem, this thesis imported matrix theory to study and discuss mathematical methods for determination of consistency and correlations of standards. Direct and indirect mathematical model for determination of consistency and correlations of standards are designed based on adjoin matrix and reachable matrix.geographic information standard; standard system; dependent context;interoperability specification; system engineering of standardization...