Shortest Path Navigation Application on GIS Supervisor: Dr. Damitha Karunaratne Thilani Imalka 2007/MCS/023

Introduction  Geographical Information Systems (GIS)  Information system  Store, capture, analyze, manage and present all forms of geographically referenced data.  Currently there are many number of GISs are available such as Google Earth, Yahoo Map etc...  Shortest Path Navigation is a main application in location based systems. Shortest path analyses - commonly based on vector maps. Used to calculate the shortest path between two points in a network or route.

Shortest Path Algorithms  In graph theory, It’s the problem of finding a path between two vertices (or nodes) such that the sum of the weights of its constituent edges is minimized.  Ex: On a road map; vertices  locations & edges  roads.  Dijkstra's algorithm –  Solves the single-source shortest path problem, with non negative edge path costs, common in routing.  Bellman-Ford algorithm  Label correcting algorithm, computes single-source shortest paths in a weighted digraph  A* search algorithm, Floyd Warshall algorithm and Johnson's algorithm.

Goals and Objectives  Goals  Design a user friendly; web based application to calculate the shortest path or route between user given locations.  Returns a map with the shortest route being highlighted.  To calculate the shortest path, we’re going to use the famous shortest path algorithm, Dijkstra’s.  Objectives  Maximize efficiency.  Minimize Cost.  Improve quality of service.  Manage resources.  Effective emergency response.  Safety of citizens.

GIS Navigation related Applications  MapQuest  Its a map publisher and a free online Web mapping service owned by AOL.  Lets users automatically find their locations and locate nearby points of interest; ex: airports, hotels, banks and ATM  Google Maps  Free web mapping service application and technology provided by Google.  Google street view is a new feature of Google Maps which provides 360 panoramic street-level views of various U.S. cities.  Yahoo Maps

Scope  User should enter the exact starting location and end location in the given GUI (text boxes).  Locations should be given as coordinates or by using the pointing device (mouse) to the location.  System supports only for a single end location, not for multiple destinations at a time.  Output will highlight the shortest path and display with the distance. But not display directions, estimated time for the journey etc…  If the given locations are not located exactly on the road, the system will calculate the nearest road for those locations first.  If there are more than one shortest path for given locations, then the system will display all of them to the user.  Client program is giving a facility to enter information about the locations for authorized users.

Related Technology  PostGIS  PostGIS is a database which is supporting for Geographic Information Systems.  Extension for well known PostgreSQL object-relational database  MapServer  Open Source development environment for building spatially- enabled internet applications.  OpenLayers  Pure JavaScript library for displaying map data in most modern web browsers  No server-side dependencies.

Thank You !!! QUESTIONS???