Development Of Quality Checking System For DLG Data Based On Arcengine

In the process of spatial data processing, the procedure such as vector quantization, theconversion of data format, the establishment of topological relation will inevitably appearerrors, as the core of basic geographic information, the data quality of digital line graph (DLG)has directly effects on the application in all fields. As a result, how to improve the efficiencyof DLG data inspection, the accuracy and completeness of DLG has always been a hot issuein the field of GIS theory and technology research.At present there are a lot of systems that inspect the data quality of DLG, but there aresome deficiencies in fields such as the comprehensive of examination content, the degree ofautomation, the ease of use, and the visualization of the check results, etc. In this paper theaccuracy of mathematical data and attribute data of DLG, and the continuity of logical,completeness, accuracy and correctness of quality inspection content of DLG had beenstudied, then the author has realized the system of accuracy and quality check of DLG databased on the ArcEngine. The main contents are as follows:1. On the illustration of the basic concept data and the data model of DLG, and accordingto the national spatial data quality inspection standards, this paper expound the quality ofDLG data from checking its mathematical precision, attributes precision, logical consistency,completeness, accuracy and correctness.2. This paper according to the principle of how to design the GIS system, and follow theprinciple of system design project, using the method of designing object-oriented system,carried out the overall design and module partition of the system, finally design the module ofgraphic display and operation, the module of DLG quality inspection, and the module ofsystem and check the settings in detail, these are the three major functional modules in thissystem.3.The contradiction between dot and line, the pseudo node, the self-intersection, and thespatial relations of polygon are the key issues in the quality inspection function, after thecomprehensive comparison for the characteristics in several existing algorithms, this paperadopt TIN detection algorithm of contour structure solve the problem of the contradictionbetween dot and line; use the monotone chain inspection algorithm solve the problem of intersection; make use of the background graphic quickly check algorithm realize the spatialrelations check surface crack and overlap.4. Based on ArcGIS Engine, make the use of VC++6.0development tools for systemdevelopment, this system has realized the conventional map operations, and solved problemsabout the contradiction between dot and line, the spatial relations of polygon, the pseudonode, the self-intersection, and realized the function of system checking and setting.In this paper, a DLG data quality check system has been realized. This system has thecharacteristics of comprehensive, efficient, and can basically meet the requirements of dataquality examination.