network and geocoding Flashcards
network data model
connected set of linear features formed from vector lines
topology is an essential property
defining a network
set of edges connected to form joins and loops
also called a graph
types of graphs
undirected
directed
planar
non-planar
edges and nodes
edges: links, chains, connections, relations
nodes: points, junctions
representing the network data model (geometry)
nodes: intersections and interchanges
arcs: linear features connecting node pairs
stops: locations on a network where people or goods are transferred
centre: locations of resource supply/distribution facility
turns: transition points from one network arc to another
representing network data model (attributes)
distance: euclidean distance along the network segment
attractiveness: the relative importance of one node to another
impedance: cost/time traversing a network arc
supply: node that provided some g/r
demand: node that needs some g/r
shortest path
min distance or cost-path b/w an origin node and destination node
emergency planning
travelling salesman problem
what is the least-cost round trip starting at one point, visiting each location once and returning back to the starting point
delivery of goods
geocoding
process of assigning a point location within a coordinate system
2 types of geocoding processes
direct and continuous: lat/long or projection coordinates - precise and continuous
indirect and discrete: street addresses, CT, ZIP codes - accuracy depends on geocoding system - difficult to locate on digital maps
categories of spatial referencing systems
census geography
geocoding
spherical and planar coordinates
census geog
postal codes, census tracts CT, dissemination areas DA
geocoding
postal address, postal codes, coordinate geometry COGO
spherical and planar coordinates
lat, long, UTM
errors associated with geocoding
errors in addresses
accuracy and precisions of network file
