Tài liệu Slide building generalizated tool for road data of big scale topographic map

The 14th Conference on Science and Technology HCMC University of Technology Section of Geomatics Engineering BUILDING GENERALIZATED TOOL FOR ROAD DATA OF BIG SCALE TOPOGRAPHIC MAP Nguyen Thi Lan Thuong1, Vu Xuan Cuong2 (1) Faculty of Land Management and Real Estate, Nong Lam University of HCMC (2) Ho Chi Minh University for Natural Resouces and Environment Why do we generalizate? Satellite image Map On satellite images, aerial photographs, no content selection as shown. Also on the topographic map, content must be selected, generalized as shown. www.trungtamtinhoc.edu.vn The same area with different map scale - decreasing the level of detail to ensure the readability of the map. So we must generalize. www.trungtamtinhoc.edu.vn What is generalization? Generalized map is selection and generalization of objects that are displayed on the map to suit the purpose of use, scale, subject map and characteristics of territories. www.trungtamtinhoc.edu.vn Generalizated form  Simplification  Smoothing  Amalgamation  Aggregation  Merging  Collapse  Selection  Exaggeration  Enhancement  Displacement  Classification  Symbolisation www.trungtamtinhoc.edu.vn Some softwares have generalizated tools Mapinfo Microstation ArcGIS I selected ARCGIS software to study www.trungtamtinhoc.edu.vn Generalizated tools in ARCGIS software In ArcToolbox of ArcGIS, generalizated tools are organized into Generalization toolset www.trungtamtinhoc.edu.vn Knownledge map Generalization: complicated Problem Use ARCGIS software Not easy! Know how to use software Knownledge About quota generalization Knownledge About quota generalization www.trungtamtinhoc.edu.vn Knownledge map I built generalizated tool for big scale topographic map in ARCGIS software Road data Residential data River data Process of generalization www.trungtamtinhoc.edu.vn Solution for road data Generalizated form Objects Keep (maintain) Railroad in Station ; Notes; Past; Bridges; Street under water; Harbour; Dock; Lighthouse; Dangerous areas Eleminate reject Float bridge past railroad; Intersection of street and railroad; Beacon; Milestones; road sign, Pavement, Roadside; lane, park… Change symbols Types of railroad www.trungtamtinhoc.edu.vn Solution for road data Count width of objects and collapse dual lines to centerlines Land road ; Gravel road; concrete, asphalt paved road; Deep slit road, … Reject depend on length, density. Then collapse dual lines to centerlines Big land road Reject depend on length, density. Simplification Change symbols Land road, trail, foot path www.trungtamtinhoc.edu.vn Solution for residential data Generalizated form Objects Aggregate blocks of house If distance between buildings < 0,3mm  gather to block Fire – resistant houses Block of fire – resistant houses Less fire – resistant houses Block of fire – resistant houses Reject Unexpected house A map only has less 5 ones Reject If area < 1mm2 Houses that don’t have wall Reject If area < 2mm2 Broken houses Reject Eaves, Steps, Outdoor stairs, Tanks www.trungtamtinhoc.edu.vn Solution for river data Generalizated forms Objects Reject If area < 2mm2 Ponds, lakes Simplification Road edge of river Reject if area < 15mm2 Coral beach, Seaweed beach, riverside beach Reject if length <5mm Dike Collapse dual lines to centerlines Channel, drain www.trungtamtinhoc.edu.vn Project for road data www.trungtamtinhoc.edu.vn Project for residential data www.trungtamtinhoc.edu.vn Project for river data www.trungtamtinhoc.edu.vn Design function Data function - Data conversion - Merge maps - Select coordinate system map … www.trungtamtinhoc.edu.vn Generalizated function •Select and reject road (minimum length) • Collapse dual lines to centerlines • Simplification • Aggregate buildings • Select and reject river (minimum length, density, area) … Function after generalizated - Find overlapping error - Displacement - Update attribute - Evaluate result of generalization tool Building menu www.trungtamtinhoc.edu.vn Building tools:  Tool for data conversion  Tool for merging maps  Tool for selecting map coordinate system  Tool for importing quota of generalization  Tool for generalizated map Tools after generalization     Tool for finding overlapping error Displacement tool Tool for updating attribute field Tool for evaluating result of generalization www.trungtamtinhoc.edu.vn Building tools for data conversion www.trungtamtinhoc.edu.vn