International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004 
  
boundaries of these features are not always the road segments. 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
That’s complicated and may cause data redundant. i 9 J 
In this paper, the authors proposed three topological tables oe) 
suitable for ITS application and one efficient algorithm for l a4: x b 3 d 4 
constructing such tables. c 
3. TOPOLOGICAL DATA MODELS FOR ITS 74 
APPLICATION 5 6 |g 7 
Topological Data Model is the foundation of topology generation. (a) A graph containing node, edge and polygon 
While constructing topological data model, we need to select Edge-node Topology 
feature types and topology according to the requirements of 
certain application. In the case of ITS, most popularly used data Edge ID From Node End Node 
model is GDF (Geographic Data File) model, defined in ISO IS a | 2 
14825. In GDF data model, three types of graph topology are b 2 3 
defined, that are non-explicit topology, connectivity topology, C 2 10 
andiifultitopélogy: Compared with fhe-other &wodtypes, full —  —— — | — cc | /— nomm 
topology can perform network operations in a very efficient way, (b) Edge-node topology 
and also can integrate area information in network operations. 
  
Node-Edge Topology 
  
  
  
  
  
According to the definition of full topology and the Node ID Associated Edge 
characteristics of ITS application described in section 1, we 2 a, b.c 
define three tables to store the topological relations between the 3 b.d,e 
features in ITS applications (Fig. 2). The first one is edge-node 10 cg f 
topology to record From-Node and End-Node of enebedueh — | | |... | |... .. 
  
  
  
  
Another is node-edge topology to record edges at one node. And 
the third one is 'special' area topology. The former two are (c) Node-edge topology 
similar to the definition in the past, but the last one is different. In 
  
  
  
  
  
  
the past, the ordered set of boundaries of area features are Special Area Topology 
searched and stored in area topology. However, because arca identified Point ID Around Reads 
features themselves are not required in ITS application, the A (hd bol 
traditional area topology isn't necessary. The "special" area B beri arb 
topology proposed here only records the relationship between C died 
area features and road segments. Then, not the relationship 
  
  
  
  
between all area features and road segments are required. So, the 
required area features need to be identified and the relational 
(d) Special area topology 
$ € ed ified points and the around road segments : 5 ; 
te s : 5 Fig. 2 The topological tables defined in our methods 
need to be built. These topological relations are described in the 4. ALGORITHM FOR BUILDING FULL TOPOLOGY 
following tables. 
4.1 Overview 
The foundation of this algorithm is the topological relation tables 
described above. It works on the premise that all roads have been 
broken at the intersection. The input data include the coordinates 
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