GISData Preparation and Integration课件.pptVIP

GISData Preparation and Integration Digesting the Food 精品文档 Data Preparation and Integration: the necessary steps Geocoding: assigning geographic coordinates to points Perhaps the most basic form of spatial data entry data media conversion scanning digitizing data format conversion raster vector data reduction Topology, error detection and topological editing rectification and registration (one on top of the other) overlaying sheets and referencing to the real world edge matching image adjustment (side by side) linking balancing adjacent sheets interpolation conflation 精品文档 Geocoding:assigning spatial coordinates to point data Address Matching assigns spatial coordinates (explicit location) to addresses (implicit location) Address matching requires street network file with street attribute information (street name and number range) for all street segments (block sides) “Zone” variable required if data spans multiple cities (to handle duplicated street names) precise matching of street names can be problematic completeness (esp. for ‘new’ streets) important PO boxes, building names, and apartment complex names cause problems. Implementation in ArcGIS is 3-step process In ArcToolbox (9.2), process street network file to create a Geocoding Service In ArcMap, load appropriate geocoding service via Tools/Geocoding/Services Manager In ArcMap, geocode a table of addresses using Tools/Geocoding/Geocode Addresses Point Location Files containing lat/long or x,y coordinates (e.g derived via GPS) bring table (e.g. in .csv or .dbf format) into ArcGIS using add data icon Right click table name in T of C and select Display X,Y data Displays as “event layer.” Export to shapefile or gdb feature class for spatial data set. Input table must contain 3 variables at minimum: Feature ID, x, y 精品文档 Data Media Conversion--Scanning:automated recording of map or aerial Produces “dumb” raster data vectorize using conversion software Create “smart” image