Research On Architecture And Its Key Technique Of "One Source, Multi Representation" Chart Production

Digitalization means converting paper data into digital data, while informatization aims tointegrate data based on digitalization, to ensure consistency, updating in time and highefficiency of the data. China charts production has been realized digitalization, howevercompared with developed countries, some technologies are still lagging behind, such as lowefficiency, not timely data update as well as data inconsistency in different products. In order tosolve these problems, a solution is proposed in this dissertation, as well as its key problems.The main works are as following:1. Four issues related to modern chart production－"chart product architecture","chartdata model","auto generalization algorithm","matching algorithm of spatial data" aresummarized and analyzed in the front of this dissertation.2."One Source, Multi Representation" Chart Production System is proposed, including itsconcept, theory architecture, main process and key technique.By multi-source chart data fusion,this production system can ensure all the source data be unique, update in real-time, all theproduct data be consistent; it allows product data derivating from another product data, whichavoid difficulty from producing product data from source data of larger scale;"Geometry SharePool" realizes geometry share among different product data, which ensure all the product databe consistent.3."Entity Model" is redundant in geometry and has problem of topological inconsistency，and "Topology Model" is redundant in topological relation and its realization and operation isvery difficult. So, an seamless, scaleless, not layered, and irredundant geospatial data model－"Seamless, Scaleless Source Data Fusion Model" is promoted in this dissertation, which can notonly integrate various chart data,but also avoid data redundancy or relation redundancy intraditional data models. Considering the international chart standard of S-57and S-100, afeature data model and attribute data model of chart is given, and a spatial data model withminimized topology is brought out too. According to "Seamless, Scaleless Source Data FusionModel", a schema of chart source database is put forward: chart data semantic is unified byestablishing chart concept collection and features catalogue, seamless and scaleless chart sourcedata is constructed by decoupling feature collection and spatial geometry collection.4. After analyzing the transfer relationships of different chart data, the dissertation putsforward a XML-based transfer language, which is consisted of pronoun, noun, adjective,condition sentence, operation sentence and other syntax structures, feature and attribute can betransferred automaticlly by this language; by topology reconstruction, spatial schema can be transferred automatically. With the XML-based transfer language and topology reconstruction,transforming from CDC, DNC and other exterior data to chart source data can be the realized.Automatic feature matching method between new data and data in source database is alsoresearched, and a new line feature matching method based on "improved Hausdorff distancebased on error theory" is put forward in this dissertation. At last, chart data quality evaluationcriteria are given.5. In order to produce product data from source database, chart soundings’ selectionmethod is researched in this dissertation. By analyzing existing research on soundings’ selection,we can draw a conclusion that the traditional soundings’ selection method taking soundings asplane points and lay stress on spatial distribution characteristics, which causes soundings’ autoselection difficult to practical; and space points’ selection, and then an idea of how to selectsoundings is put forward. In view of existing shortcomings of soundings’ auto selectionmethods, an idea of select background soundings in space points, in order to preserve seabedcharacteristic, is advanced, then based on Delaunay triangle net and local dynamic update, aprogressive method of soundings’ auto selection base on TIN surface is put forward, thenseveral experiments with "minimum curvature limit","average spacing limit","depth valuechange limit", and all these limit combined are carried out and compared, from which we candraw a conclusion that sounding selection in combined limit has better effect.6. In order to update product data once source database changes, a method to update curvein product is researched. Based on construction of Constraint Delaunay Triangle Net, Bend-Binary-Tree of curve can be built, that is called CDT-Btree. Optimization of CDT-Btree can becarried out by resembling, branch node adjustment, then a Multi-way Tree, called CDT-Mtree,can be built after neighbor bends recognized, which represents the curve bend characteristiccompatible with visual perception. Based on CDT-Mtree method, an incremental updating andincremental generalization method is proposed with the basic element of curve bend. With themulti-level curve bend matched, the change between source curve and product curve bend ismatched and recognized.7. An experience conforming to "One Source, Multi Representation" Chart Production iscarried out. A basic chart source database is built from DNC and CDC experiment data; themain regulation on data content of ENC product specification is introduced; then twoexperiment about chart production and update from source database is introduced taking ENCas an example, which proved the feasibility of "One Source, Multi Representation" chartproduction.