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Route Finding Using Geographic Information System

1. Servers 1 E A PostgreSQL Database Server 8 3 localhost 5432 m Tablespaces US A Group Roles p A Login Roles Name the database testdb and for the template select template _postgis Click OK E New Database Y our pgAdmin should look something like this 93 E 1 pgAdmin Ill File Edit Plugins Yiew Tools Help PO a Object browser Servers 2 PostgreSQL 8 4 localhost 5432 EN 8 Databases 3 Sy Tablespaces 2 Group Roles 0 Ho Login Roles 1 PostgreSQL Database Server 8 2 localhost 5432 E B Databases 4 pastgis 3 postgres template_postgis a Sy Tablespaces 2 Group Roles 0 Hdt Login Roles 1 Step 3 Add the core pgRouting functionality to the newly created database In pgAdmin III select the newly created testdb database in the object browser Look at the top toolbar in pgAdmin III There is a SQL query tool Click on this tool to open it or click Tools gt Query Tool from the application menu In the SQL query tool window click File gt Open and select C Program Files PostgreSQL 8 4 share contrib routing core sql To execute this query click the green play button or navigate the application menu by clicking Query gt Execute Repeat the same process for C Program Files PostgreSQL 8 4 share contrib routing core wrappers sql C Program Fil
2. available from the server e Format specifiers which include valid output formats for an operation supported exception formats and the format of context at URLs 2 9 3 1 2 GetMap The GetMap operation allows to return a map to the user s client application The GetMap operation provides the parameters which are outlined in table 2 2 to allow the 26 user to send a GetMap request to a web map server to retrieve a map OGCWMS1 3 p32 The response of which is a map of spatially referenced information based on the parameters specified in the request Request Parameter Mandatory Description Optional LAYERS layer_list uM Comma separated list of one or more map layers STYLES style_list Comma separated list of one rendering style per requested layer CRS namespace identifier Coordinate reference system BBOX minx miny maxx maxy is m m O Bounding box corners lower left upper right in CRS units WIDTH output_width Width in pixels of map picture HEIGHT output_height Height in pixels of map picture FORMAT output_format EMS O Output format of map TRANSPARENT TRUE FALSE Background transparency of map default FALSE BGCOLOR color_value Hexadecimal red green blue color value for the background color default 0xFFFFFF EXCEPTIONS exception_format The format in which exceptions are to be reported by the WMS default XML TIME time ae Time value of layer desired ELEVATION elevation O Elev
3. 5 2 Setting data for pgrouting After the data is imported in spatial database usually requires one more step for pgRouting to work For pgRouting to work edges table should contain the network topology or connectivity information data should provide the network topology which consists of links to source and target id each So first source target and length column is added as shown in listing 5 3 and then the assign_vertex_id function is ran This function assigns a source and a target ID to each link and it can snap nearby vertices within a certain tolerance ALTER TABLE dublin highwayl ADD COLUMN source integer ALTER TABLE dublin_highwayl ADD COLUMN target integer ALTER TABLE dublin highwayil ADD COLUMN length double precision Listing 5 3 shows that the table was successfully altered Now road data contains source target and length column 58 estdb Md dublin_highwayl Table public dublin_highwayi Column i Type Modifiers a a a a a a a a a a a a a a A A A A A A A a e a a a a a a a a a a a a a a a a a a a a a a a a a gid i integer i not null default nextval dublin_highwayl id_seq regclass Sid bigint i gid i character varying 5 gt i gid character varying 5 i id i character varyingt b5 gt i type character varying 13 i name character varying 34 i oneway character varying 4 gt i the_geom i geometry i source i integer i target i integer i length i double precision i Inde
4. Route Finding Using Geographic Information System Abstract The main goal of this work is to find shortest route between one building to another first at the desktop environment and then using the Web map service The research part of this work will comprise of a look at Geographic Information systems GIS technologies including advantage of using GIS GIS Web services and how these interact with each other will also be discussed Following this the GIS standards will be discussed with a more detailed discussion on OGC simple feature specification WMS and WFS The practical part of this work will comprise of setting up a hardware and software environment Components integrated in the system include a spatial database PostGIS OpenJump a GIS server GeoServer and front end technology OpenLayer Following this an exploration of the environment will take place in the form of practical hands on use of the software to build an understanding of how the research can be applied in a practical way The streets use OSM data from CloudMade and the buildings data are a subset of the Geodirectory from An Post originally Keywords Open Source pgRouting GeoServer OpenLayers route finding Table OF UG UGS 25528055 AAA 5 Chapter dis Introduction x didas 8 LI AIM i cet tas Rican E E a ace Data wa aces ral 8 ER ODIN a A A reheated AE 8 LS lOs a obs 9 t4 MAI oe 10 1 5 Project Mana E A aos 11 1 6 Overview OF the architecture used iris iaa 11 If Repot
5. The view was then can be viewed from the OpenJump and for that the following o query was passed from the OpenJump query tool select asbinary h the_geom from route r dublin highway h where h gid r edge_id H Ji Working a a y a maana E Y route r dublin_highwa A sf e z P 7 ll E i o route r dublin_highwa i i H aan x E E E 4 buildings _geodir ewe 7 a a of P System a m y a g oo z J E Sine A po a a om a 1 co 3 Loft A tg y ee a e 8 A Y y is 1 44 a Figure 6 1 showing the the shortest path between two buildings with gids 1375 and 59 in OpenJump 6 2 OpenLayer Code This section explains interface design code It includes HTML CSS and javascript code JavaScript was selected as it s provides functionality need to keep track of mouse position or capture when someone clicks the mouse or execute something when the page is fully loaded Therefore JavaScript was used in conjunction with OpenLayer API to load the map and enable user interaction 73 lt div id map gt lt div gt This lt div gt element will serve as the container for map viewport lt style type text css gt map width 500px height 500px border 1px solid black lt style gt In this case we re using the map containers value as a selector and map is specified with the width 512px and the height 256px for the map container and 1 px for the border
6. controls start new OpenLayers Control DrawFeature start SinglePoint stop new OpenLayers Control DrawFeature stop SinglePoint TT for var key in controls map addControl controls key This section deals with vector layers where the data is rendered for viewing in your browser The two vector layer is given a title Start point and End point respectively start new OpenLayers Layer Vector Start point style start_style stop new OpenLayers Layer Vector End point style stop_style these code provides style to the vector layer Start point and End point var start_style OpenLayers Util applyDefaults externalGraphic marker green png graphic Width 18 graphicHeight 26 graphic Y Offset 26 graphicOpacity 1 OpenLayers Feature Vector style default var stop_style OpenLayers Util applyDefaults externalGraphic marker png graphic Width 18 graphicHeight 26 graphic Y Offset 26 graphicOpacity 1 OpenLayers Feature Vector style default 78 OpenLayers provides controls for drawing and modifying vector features The OpenLayers Control DrawFeature control can be used in conjunction with an OpenLayers Handler Point an OpenLayers Handler Path or an OpenLayers Handler Polygon instance to draw points lines polygons and their multi part counterparts The OpenLayers Control ModifyFeature control can be used to allow modification of ge
7. location under your PostgreSQL installation which should be e Copy the DLL files to C Program Files PostgreSQL 8 4 lib e Copy the SQL files to C Program Files PostgreSQL 8 4 share contrib e These folders are shown below 93 I priss_files 5 processPINSign_files Thes files are UNZIPed to any temporary folder E Ey PostgreSQL 8508 E bin E E data E E doc E 5 include Mame e IC installer 3 librouting dll 8 388 KB Gail idbc librouting_dd dll 8 729 KB Gon 3 librouting_tsp dll 2 098 KB Co plugins E logs C pg dmin III E scripts outing_core z 5 share routing_core_wrappers 32KB SQL File J routing_topology postais The SQL files go here 9 3 Appendix C I had created separate database named testdb and postGIS functionality was added to it It is described below how it was done Start pgAdmin III a graphical tool for administering PostgreSQL databases Step 2 Create a database called testdb using pgAdmin III and add PostGIS functionality via the default template A template can be used to construct many database with the same properties e Open pgAdmin III from the Windows Start Menu Start gt Programs gt PostgreSQL 8 4 gt pgAdmin III e Connect to your database by double clicking it in the object browser You may need to enter password information e In pgAdmin II right click on Databases in the table and click New Database 94
8. polygon or multipoint 21 Figure 2 5 0penGIS Geometry Class Hierarchies OGCSES 1 1 p2 2 As it can be seen from figure that there are many different types of spatial information that can be stored in a compliant system we will be mainly concerned with points and lines Points have only an X and Y value in respect to a spatial object for buildings Whereas lines are a set of points that are grouped together in a particular sequence to give a line these would be the routes from one building to another 2 9 2 Features Table Architectures As this project data are taken in PostGIS it was necessary to understand the table structure of OpenGIS Simple Feature Specification for SQL how the geographic object are presented The figure below describes the database schema necessary to support the OpenGIS simple feature data model A feature table or view corresponds to an OpenGIS feature 22 class Each feature view contains some number of features represented as rows in the view Each feature contains some number of geometric attribute values represented as columns in the feature view Each geometric column in a feature view is associated with a particular geometric view or table that contains geometry instances in a single spatial reference system The correspondence between the feature instances and the geometry instances was accomplished through a foreign key that is stored in the geometry column of the feature table SPATIAL_REFERE
9. testdb target integer testdb length double precision as cost testdb FROM dublin_highway1 testdbC 434 12348 false false Listing 4 3 Verifying shortest_path function query successfully runs in psql Output from the shortest_path function query is shown in listing 4 4 testdht 434 12348 false false vertex_id i edge_id i cost pia a A A A A 434 1 223 1 20 5053774160766 435 1 8336 1 167 215846445198 12851 1 8261 1 352 811002783644 12655 1 86668 1 220 713677536223 12348 i i 15 5 rows Listing 4 4 Output from the shortest_path function query 53 4 8 Summary This project uses Dijkstra shortest path algorithm Dijkstra shortest path algorithm slove the single source shortest path algorithm for a graph with non negative edge path costs So this project also only returns the shortest path from the single source route 54 Chapter 5 Loading data setting data for routing and putting postgis data into Geoserver This chapter explains about how the data was loaded and stored in spatial database which is a part of procedures in GIS and the system integration between PostgreSQL PostGIS openJump Geoserver and openlayer The figure 5 1 shows the overview of system integration PostResponse Ree Web feature and Web map service layer 0 Figure 5 1 Overview of system integration 5 1 Loading Data The streets use OSM data from CloudMade The OSM data was transformed to Ir
10. 17 2011 pgRouting pgRouting Project Open Source Routing Library Available at http www pgrouting org Accessed July 17 2011 Lecture 2 2011 spatial databases lectures Available at http www comp dit ie pbrowne Spatial 20Databases 20SDEV4005 Spatial 2 0Databases 20SDEV4005 htm Accessed July 18 2011 GIS com Available at http gis com Accessed May 14 2011 OGCSFS 1 1 OpenGIS Simple Features Specification For SQL ref 99 049 http portal opengeospatial org files artifact_id 829 Accessed 15th August 2011 OGC 2002 Web Map Service Implementation Specification Available at http cite opengeospatial org OGCTestData wms 1 1 1 spec wms1 1 1 html Accessed August 2 2011 OWS 2003 Open GIS Consortium Inc portal opengeospatial org files artifact_id 1320 OGC History OGC History abbreviated OGC R Available at http www opengeospatial org ogc history Accessed August 14 2011 Carl N Reed 2011 Geospatial Web Services Advances in Information Interoperability http www igi global com viewtitlesample aspx id 5 1480 Accessed August 14 2011 Whitten J L Bentley L D Dittman K C 2001 Systems Analysis and DesignMethods 5 Ed McGraw Hill OpenLayers OpenLayers Home Available at http openlayers org Accessed August 29 2011 91 9 Appendix 9 1 Appendix A Using OpenJump with PostgreSQL PostGIS e To adda PostGIS table to OpenJump select e Layer Run Datastore
11. Overvie Woe roina a a E a a E R A a 12 2 Research O 13 2 1 Geographic Information SYM TA 13 22 Components Of Gli 14 DO SS NT EA O tae mated 15 TA Spatial Data asian 15 DESL A ae ss 16 PS RASTER A A E a A 16 215 2 Vettor datait ari a E eaten exeate E E a 16 26r Spanal A cau Gonteal at du ctansdag tenn cthas wened udaecanoapareanesedct 17 2 OpenStreetMap a eRe ney eet a RE ERT She RENE PRE Seen Meer ares ree eee ore 17 2k Data Formate A A ease tes 18 287 WCD SCTVICES ac ccstcesbasdazvss cant an re ad 19 2 9 Tnd stry Standards e es 20 2 9 1 OGC Simple Features Specification z cc s cseccccssccennsasscsevsessseeessseeicounssooenaueses 20 2 9 2 Features Table Architectures ooococccnnonononononononononononononononononononononononinononos 22 2 9 3 OGC web map service and web feature ServiCES ooooocccnocococococcconnnconnccanonnnos 23 210 A Aa A este endowed 30 Br STC USS CLUS eee o a eae EES 31 Be LARS cla hes cs ad ou a tal alt a a aah ca eae 31 3 2 SOWA E A 32 3 21 A SLOTS SO A O E A i O AANA 32 Ian ROS raat e e ata th Nearest ene eg ts 33 3 3 1 Testing PostGIS ManCiOn al ad a tcs 34 331 Standard Compliance susan 34 3 3 OpenMP es i e E e RER EE E AR A 35 3 3 1 Standard Compliance di dass 35 JA PEU Oats sch yates dots natant ati Oa sola iio 36 BD O waists A Wises a 37 39 1 Why se PEs SOU asec are cs eloded E 37 BO Fite lor eeen st es aeea ant ae eee lea Ravana anys Sa Ren aaa 38 Bek RCO Server 2N Q zg
12. Weber P OpenStreetMap User Generated Street Maps Pervasive computing IEEE vol 7 no 4 2008 pp 12 18 Bennett J 2010 OpenStreetMap Birmingham Packt publishing ESRI 201 1a ESRI Virtual Campus Available at http training esri com Courses LeamArcGIS index cfm c 188 Accessed May 21 201 1a GIS 2008 Essays on Geography and GIS Available at http www esri com library bestpractices essays on geography gis pdf Longley P A et al 2010 Geographic Information Systems and Science John Wiley amp Sons Available at http books google com books id wUkZQAAACAAJ Ian N Gregory and Richard G Healey Historical GIS structuring mapping and analysing geographies of the past DOI 10 1177 0309132507081495 Prog Hum Geogr 2007 31 638 http 0 phg sagepub com ditlib dit ie content 3 1 5 638 full pdf html ISS 2006 Information Software Systems Available at http www informationsoftwaresystems com Accessed June 4 2011 ESRI 2011b vector Available at http training esri com Courses Shared2003 vc _deftemplate cfm Term vector amp CourseKbaseID 1 Accessed June 5 201 1b Guting R H 1994 An introduction to spatial database systems The VLDB Journal 3 4 October 1994 357 399 90 FOSS4G 2011 Shortest Path search for real road networks with pgRouting Free and Open Source Software for Geospatial Available at http 2011 foss4g org sessions shortest path search real road networks pgrouting Accessed July
13. a a mqi Y Figure 6 2 Showing the road and buildings table as a layer 80 Go to a Web Site fid _gid gid gid gid type name oneway source target length dublin_highway1 8061 8058 8054 8054 8051 unclassified Peter Street 12656 12657 156 22986679429044 BUILDINGS_GEODIR fid building i group id thorfare_i post_town_ data_src_i changed da presort id postaim id ed_id name no building u n ag f buildings geodir245 36945402 40289 8 1 2005 08 108 93 268140 CHAMBERS c SS eE YI y C N Y po Re i tly Figure 6 3 Showing the features of the road and building data 81 counties ny j SX gt navigate Figure 6 4 showing the Layer switcher containing layers name Dm BES cano WE i k Y or j A h _ LE Y o ix hi A Chapter 7 Conclusions However achieving the aims of this project was very challenging since technical and non technical Challenges needed to be addressed Personal Research and reading where essential in order to succeed Most Importantly understand the concept of spatial database and Web mapping A lot of time and resources were used to investigate testing and integrating the different tools needed to support the implementation process of this project because it was difficult to implement extra features on standalone earth client without previous knowledge of PL pgSQL OpenLayers GeoServer and javascript language 7 1 Ove
14. is one of the key abilities of GIS is a specialized form of database because each item of data be it a row of statistics a string of text an image or a movie is linked to a coordinate based representation of the location that the data refer to Geogray amp Healy 2007 Thus GIS combines spatial data in the form of points lines polygons or grid cells with the attribute data held in conventional database form This provides a structure that is able to answer queries not only about what features are in the database but also about where they are located This is what makes GIS unique GIS maps are interactive On the computer screen map users can scan a GIS map in any direction zoom in and out to see different areas with more or less detail they can decide what features they want to see and how they are symbolized and most importantly they can access a database of information about all the features shown on the map GIS 2008 2 2 Components of GIS The following diagram illustrates the six component parts the geographic information systems People Procedures 14 2 3 Figure 2 1 Parts Of Gis Longely 2007 Why use GIS GIS provides numerous benefits and advantages in our daily life According Longley et al 2010 GIS 2 4 Affects each of us every day for example the energy to power the alaram comes from the local energy company which makes the use of GIS to manage all its assets Can be used to make ef
15. sects ste iain leas Delete te tes vended ad ead eta teie ed adele 38 DOs MEST CICS A A A E 39 SW AE A A Sata eta auteur cdl chance eter al ta cai ean a cote E 43 3 7 1 Openlayers and web Map i 44 3 8 SIEA at a a Ee a oh ETEA EE E EE 45 Chapter 4 Routing Algorta sia 46 MI A A i dewagalaes 46 4 2 Principle of the A Ls ld el 46 ES gt EXAMPLE A A A A A A Aaa shes Gaede 47 4 4 UML for Dijkstra s shortest path algorithm ooonconinncinncnnonoconncononononconnccononnnos 50 4S A e aa ed 51 4 6 A A e E 51 A A IR E 53 Act Query MO sa A A Meee ae 53 4 8 A A CO 54 Chapter 5 Loading data setting data for routing and putting postgis data into Geoserver LA 55 SF Loading Da od 55 5 2 Setting data dor so ee de o a 58 O A i e ys sae ae cules ei bo eve eben vs aaa e wees ea 60 5 3 Example of Spatial SQL queries nl ellas 61 5 4 Putting PostGIS data into Geoserver ii 62 5 5 A A E A TE ET 68 Chapter O rd lnea as heh ae 69 Gl PL PESOL code erionenn a a E A a take A aa 69 6 2 Openbayer Code iii ito 73 Chapter Conclusions ia see 84 TA OVERVIEW of objectives dad 84 7 4 Benefits of undertaking this projet 86 7 5 Future research could be done ni i 86 SIRENA ES AAA IRs 88 E A A O O A IIA AR 92 9 1 Appendix A Using OpenJump with PostgreSQL PostGIS ooooiocinccnnnniconncocncnnnos 92 9 2 Appendix B pgRouting Installati0O o oonocninnnnnnnnnnnonncnncnconnnonononcnnncnnacononnnonos 93 93 Appendix as 94 List of Figures Figure 1 1 Gant
16. service in a 19 manner prescribed by its description using SOAP messages typically conveyed using HTTP with an XML serialization in conjunction with other Web related standards Web services are frequently used by web application programming interfaces API s that can be accessed over a network and executed on a remote system hosting the requested GIS web services are one of the invention of the web service Google Maps and Yahoo Maps are the examples of the GIS web services GIS web services provides geospatial data on the web and as well as allow people to ask question based on the location Deoliveira This project is also based on GIS web services which is concerned with bringing World Wide Web Consortisum and Open Geospatial Consortium OGC together to provide GIS web service i e to find the shortest route between two houses 2 9 Industry Standards The Open Geospatial Consortium was founded by small group of member in 1994 OGC History with a vision to Achieve the full societal economic and scientific benefits of integrating location resources into commercial and institutional processes worldwide Reed 2011 This project adherence to the OpenGIS Simple Features Specification For SQL to support storage and query and OGC compliant GeoServer web map service WMS and web feature service WFS 2 9 1 OGC Simple Features Specification A simple feature is defined by the OpenGIS as an abstract specification
17. shortest path algorithm Lecture 6 2011 50 Figure 5 1 Overview of system integration cccccscccstecesecsseecsseeeesceceeceseceeeeeeseeesaeees 55 Figure 5 2 Geoserver datastorage s esessesesssesrsssrterestsrissetettessastestssestesseseasessesraseesaas 62 Figure 5 3Adding new workspace drid 63 Figure 5 4 Workspace Vis Wes assasedaavagecata gh Guctesadvanvissatnvarssseceds 63 a o A a E a a E Ea 65 Figure 5 6 Computing bounding boxes in Irish National Grid eee eeeeeeseeneeeneeeeeees 66 Figure 5 7 Result after the coordinate system was set to Irish National Grid 29900 66 Figure 5 8 Adding two different geometry table in one group name highwaybuildings 67 Figure 5 9 Displaying group map in openlayer format ce eeeeeeeeeeeecetecesecneeeneeeneees 68 Figure 6 1 showing the the shortest path between two buildings with gids 1375 and 59 in OV STAI UNI ie cashes cea tts AAA AAA Sas ee aan Beda AR AA hae leno 73 Figure 6 2 Showing the road and buildings table as a layer oonnonnconicinncnncnnnnnocnncnnancnns 80 Figure 6 3 Showing the features of the road and building data oonconcnncnnciocnnonnnccnnncns 81 Figure 6 4 showing the Layer switcher containing layers naM ooooconcninonoconocnnoncnncnnons 82 Figure 6 5 showing the start and end point as alayeL ooococoniconcninnnnccnoccnnnconacononononncnnnanns 83 List of Tables Table 1 1 List of Glossary Items 2 0 ic 10 Ta
18. the Java programming language openJUMP It is a vector GIS that can read raster as well SourceForge SQL queries can be issued and view directly from OpenJump which act as a client for PostgreSQL PostGIS Lecture 4 2010 However PostgreSQL PostGIS queries bring a layer into OpenJump they do not update PostgreSQL PostGIS Lecture 4 2010 Openjump was used through this project to perform analysis of datasets query the database add layer and attribute 3 3 1 Standard Compliance openJUMP supports OGC standard like simple feature interface standards SFS geographic markup language GML web map service WMS and web feature service WFS The openjump interface can be seen in figure 3 1 The data that can be seen in figure 3 1 is dublin highway and buildings geodir 35 gt OpenJUMP AE File Edit View Layer Customize Tools Window Help MARAR ESIH KGO A 7 aa 0 1 id aN Fro ee E Y buildings_geodir Figure 3 1 Openjump user interface The installation process was very easy to perform and it is supported by windows Mac OS and Linux platform it requires java 1 5 or later there is a great documentation on this website and growing user s community It can be use as GIS data viewer but has limits in reading very large data files and has limited support for cartographic projections Informer 3 4 pgrouting This project is based on route finding PostgreSQL PostG
19. workspace must be created then the data store and finally the individual layer must be loaded Workspace Data Store E Layer 1 Layer 2 Layer 3 Figure 5 2 Geoserver datastorage Step1 Login to GeoServer The defaults are username admin password geoserver 62 Step2 Create Workspace Workspaces is a container which is used to organise layer A Workspaces consists of a name and a Namespace URI In GeoServer a workspace is often used to group similar layers together Individual layers are often referred to by their workspace name colon then store Ex topp states Two different layers having the same name can exist as long as they exist in different workspaces Ex sf states topp states Geoserver 2009 New Workspace Configure a new workspace Name Ireland Namespace URI http www openplans org sushma The namespace uri associated with this workspace Default Workspace Figure 5 3Adding new workspace Ireland After clicking submit the newly created workspace appears as follows Workspaces Manage GeoServer workspaces Add new workspace Remove selected workspace s lt lt lt 7 gt gt gt Results 1 to 8 out of 8 items Sea Figure 5 4 Workspace view 63 Step 3 Add new store A store connects to a data source that contains raster or vector data A data source can be a file or group of files such as a table in a database a single file such as a
20. Addison Wesley Longman Inc Purchase H C Colpoys L McGill M Carrington D and Britton C 2001 UML class diagram syntax an empirical study of comprehension School of Information Technology and Electrical Engineering University of Queensland Obe O R and Hsu S Leo 2010 PostGIS in Action Manning publications FOSS4G 2011 Shortest Path search for real road networks with pgRouting Free and Open Source Software for Geospatial Available at http 2011 foss4g org sessions shortest path search real road networks pgrouting Accessed July 17 2011 Geoserver 2 1 0 Overview GeoServer 2 1 0 User Manual Available at http docs geoserver org 2 1 0 user introduction overview html Accessed August 13 2011 88 OpenJUMP OpenJUMP GIS Available at http www openjump org index html Accessed July 21 2011 Informer OpenJUMP Software Informer version 1 2 information Available at http openjump software informer com 1 2 Accessed July 21 2011 PostGIS PostGIS Home Available at http postgis refractions net Accessed May 14 2011 PostgreSQL 1996 2010 PostgreSQL About Available at http www postgresql org about Accessed July 21 2011 SourceForge SourceForge net What is OpenJUMP jump pilot Available at http sourceforge net apps mediawiki jump pilot index php title What_is OpenJUMP Accessed July 21 2011 Windows 7 Windows 7 Microsoft Windows Available at http windows microso
21. IS doesn t automatically provides the routing functionality so pgRouting was installed for that pgRouting is an extension of PostgreSQL and PostGIS It adds a geospatial routing functionality to PostGIS FOSS4G 2011 pgRouting is open source available under GPLv2 license pgRouting includes three types of shortest path search algorithm FOSS4G 201 1 36 e Dijkstra e A Star e Shooting Star As author had previous knowledge of shortest path queries using Dijkstra shortest path so it was chosen among those three algorithms Dijkstra algorithm is explained in chapter 4 3 5 PL PgSQL PL pgsSQL is a extension to SQL Geschwinde amp Sch nig 2001 This language initially written by Jan Wieck offers the programmer far more execution potential than SELECT INSERT or UPDATE commands It is a loadable procedural language A procedural language is a programming language where sequence of steps are specified and followed to produce an intended programmatic result CMD 1997 PL pgSQL is the only PL language installed by default for PostgreSQL so no extra effort was required to install this language as a part of this project but many others are available including PL Java PL Perl pIPHP PL Python PL R PL Ruby PL sh and PL Tcl PostgreSQL 2011 3 5 1 Why use PL pgSQL PostgreSQL is compatible with all data types operators and functions within PL pgSQL code The SQL in PL pgSQL is indicates of the fact that a
22. In Line 7 and Line 8 SELECT clause selects desired column source from table dublin highway1 WHERE clause specifies the required condition for rows here the condition is buildings gid from the table buildings_geodir which should match with the argument gid at the time of function call This query involves spatial join between two tables spatial join is done between two spatial table dublin highway1 and buildings geodir spatial predicate Contains is used for spatial join to test wheather the dublin _highwayl geometry contains another geometry buildings _geodir spatial operator Buffer is used to buffer within the 30m of the building with gid and then finally through this query find_nearest_road function returns the source of the road order by source and limiting the result to return only one row After calling this function passing building gid as an argument find_nearest_road in psql shell returns the source of the road from the dublin _ighway street table Listings below shows the function find_nearest_road returning the source 12348 and 433 of the buildings with gid 1375 and 59 respectively estdb select find_nearest_road 1375 gt find_nearest_road 1 row Listing 6 2 calling find_nearest_road function with gid as argument estdb H select find_nearest_road lt 59 gt find_nearest_road Ci row Listing 6 3 calling find_nearest_road function again with another gid as argument 70 6 1 2 find_ro
23. Max Y 297 730 375 217 955 328 330 136 625 260 578 453 Coordinate Reference System EPSG 29900 Find P5G 7M65 Irish National Grid Generate Bounds Add Layer Layers Ireland dublin_highway1 o line o t Ireland buildings_geodir point gt gt Results 0 to 0 out of 0 items Figure 5 8 Adding two different geometry table in one group name highwaybuildings By viewing the highwaybuildings group map in Layer Preview selecting OpenLayer format got both data were displayed as shown in figure 67 Scale 1 595K 315015 72778 247924 71277 Click on the map to get feature info Figure 5 9 Displaying group map in openlayer format Figure 5 9 shows the both data dublin _ highway1 and buildings geodir from postgis spatial database were successfully integrated with GeoServer 5 5 Summary Creating a GIS involves integrating multiple technologies Each of these has to be configured to communicate with each other to allow automated flow of data throughout the system 68 Chapter 6 Code The main aim of this project is to find route from one building to another building using PostgreSQL PostGIS initially display the routes in OpenJump and then display the routes using openlayers I have already explained how the data were loaded in database Now this chapter explains the languages that were used in this project to meet the main objectives of this project 6 1 PL pgSQL code PL pgSQL
24. NCE SYSTEMS SRID AUTH_NAME AUTH_SRID SRTEXT Figure 2 6 Schema for feature tables under SQL92 OGCSFS1 1 p2 20 2 9 3 OGC web map service and web feature services 23 GeoServer forms a core component of the Geospatial Web by providing the reference implementation of the Open Geospatial Consortium OGC Web Feature Service WFS and Web Coverage Service WCS standards as well as a high performance certified compliant Web Map Service WMS GeoServer 2011 However for this project we are only concerned with the Web Map Service and Web Feature Service Figure 2 10 3 below shows the OGC Web Service Architecture which displays how the specifications are related to each other and also the operations that each one defines Symbols Abstract Service OperationO G E Service eneralization GetCapabilities O OGC Web Service Web Web Web Web Registry Map Feature Coverage Service Service Service Service GetDes criptor GetMap GetFeature GetCoverage RegisterService GetFeaturelnfo DescribeFeatureType Styled Layer Descriptor Transaction WFS GeoCoder Service DescribeLayer l LockFeature A Transaction GeocodeFeature Figure 2 7 The OGC web service architecture OWS 2002 Generally the interaction between the Client and Server in both the Web Feature Service and Web Map Service as defined in their respect
25. Query e The first time you do this you will have to establish a connection with PostgreSQL PostGIS Caching F Cache features Gamel e Inthe Run Datastore Query Window click on the icon on the top right 2 small disks e This will open the Connection Manager e Click Add PostGIS vw localhost testdb User postgres Password eeeeeeee 92 9 2 Appendix B pgRouting Installation The Zip contains source SQL files and Windows DLL files E WinZip Pro pgRouting 1 03_pg 8 4 2 zip File Actions View Jobs Options Help Seascaa New Open Favorites Add Extract Encrypt Type ai I Application E e 19_dd dll Application E 3 librouting_tsp dll Application E README routing ROUTING File E routing_core sql SQL File E routing_core_wrappers sql SQL File E routing_topology sql SQL File lt Modified 27 01 2010 10 30 27 01 2010 11 21 27 01 2010 11 11 04 09 2008 13 21 04 09 2008 13 21 04 09 2008 13 21 04 09 2008 13 21 View CheckOut Wizard Size 8 589 251 8 937 540 2 147 750 19 286 3 592 32 608 2 983 Y 6 gp View Style Ratio 86 86 1 74 69 67 90 62 1 1 Selected 0 files O bytes Total 7 files 19 271KB e Unzip extract to a folder say pgTemp e The extraction process will make two sub folders called lib and share e You should copy the DLLs and SQL files provided in these folders the correct
26. ation of layer desired Other sample dimension s E aaa Value of other dimensions as appropriate Table 2 2 The Parameters of a GetMap request OGCWMS1 3 p33 The response to a valid GetMap request is a map which corresponds to spatially referenced information layer requested in the desired style and having the specified coordinate reference system bounding box size format and transparency OGCWMS1 3 p37 An invalid GetMap request shall yield an error output in the requested Exceptions format or a network protocol error response in extreme cases 2 9 3 1 3 GetFeaturelnfo GetFeatureInfo allows to get information about previous map requests An example of this is that when a user sees a map they can click on a point on this map to obtain more information OGCWMS1 3 p38 It provides the possibility of the client to request 27 the details of geometry in the map through a mouse click at an XY coordinate on the active map layer on screen The parameters of a GetFeatureInfo request are listed in Table 2 3 Request Parameter Mandatory Description Optional map SEUEST Seestenie part Partial copy of the Map request parameters that generated the map for which information is desired QUERY_LAYERS layer_list a cones ee ve ee Comma separated list of one or more layers to be queried INFO_FORMAT INFO_FORMAT output_format format mMm Retum format of feature information Return format of feature information MIME
27. b map Client OpenLayer as a client handles to ask a mapserver what a user wants to look at and all this is possible through asynchronous JavaScript AJAX calls to a map server OpenLayers sends requests to a map server for map images every time a user interact with the map then OpenLayers pieces together all the returned map images so it looks like one big consistent map 3 7 1 2 Web map Server A map server or map service provides the map itself There are many different mapserver backends For example WMS Google Maps Yahoo Maps ESRI ArcGIS WES and OpenStreet Maps With OpenLayers user can use as many different backends for map server For this project I am using OGC WMS server However the basic principle behind all those map service is that they allow to specify the area of the map the user is interested in by sending a request and then the map servers response by sending the map image OpenLayer is not a web map server it only consumes data from them To work with map server using OpenLayers just supplying a URL in it is enough 44 3 8 Summary There are many different options that can be used for each component of the GIS However a GIS will always contain an integration of hardware software data and procedures 45 Chapter 4 Routing Algorithm There are many options for routing algorithm This chapter explains the routing algorithm chosen for this project 4 1 Shortest Path Dijkstra Dijkstra s algorith
28. ble 2 1 The parameters of a GetCapabilities request OGCWMS1 3 p21 26 Table 2 2 The Parameters of a GetMap request OGCWMS1 3 p33 coocccinncniociconccnno 27 Table 2 3 The parameters of a GetFeatureInfo request OGCWMS1 3 p39 28 Table 3 Hard Wa 32 Table 3 2 Software Applications used in SYSteM ooooonccnoccnocccnoncconncconocono nono nonnncconocnnnccnnos 32 Table 7 1 Objectives and their corresponding Deliverables of the project 85 Listings Listing 3 1 Verifying PostgreSQL database is working properly ooooonoccnnncninccconncconacno 33 Listing 3 2 Verfying PostGIS functionality 20 0 ese eceeccesecetecneeeeeeseeeecesecesecneeeaeeseeees 34 Listing 3 3 Showing the version of PostGIS 0 eee eseeceeeeceseceeecneeeeeeeseceaeceeeaeeeneeenees 34 Listing 4 1 Shortest path function declaration ce eecesecesecseeeneeeeeeeeeeeeceaecneeeneeeeeeerees 51 Listing 4 2 Verfying all of the arguments from shortest_path function are displayed as a result of query from road data dublin highwayl ooooccnnncnincononcninccnnncconncconacancnonnos 52 Listing 4 3 Verifying shortest_path function query successfully runs in psq 53 Listing 4 4 Output from the shortest path function QUETY oocooccnoccconconncconocancninncconncnnno 53 Listing 5 1 Verifying successful data imports to POStQIS cc eeeeeeereeeeceteceeecneeeseeeneees 56 Listing 5 2 Verifying su
29. ccessful data imports to POStQiS ee ceeeeeeteeeeeeeeeeneeeeeeeeees 57 Listing 5 3 shows that the table was successfully altered Now road data contains source target and length columnis nai ianari aare ai A aE A Aana a Arai tS 58 Listing 5 4 Verfying table dublin highway1 was successfully altered adding source target and length CTIA edn ca ES 59 Listing 5 5 Verfying the network topology was successfully created in psq 60 Listing 5 6 Verifying the network topology was successfully created ooooooonnoninnnnnn 60 Listing 5 7 Verifying the lengths column has updated successfully ooonoononnnnnnnnn 60 Listing 5 8 Command to create index for the geometry ooooocococccococononcoonoconocana nina ncnnncnno 60 Listing 5 9 Filling out the form for the new data source cooooonconoconoconocconcoonconanononononnnonncnns 64 Listing 6 1 find nearest road function dt a yembaatsn 69 Listing 6 2 calling find_nearest_road function with gid as argument ce eeeeeeeeees 70 Listing 6 3 calling find_nearest_road function again with another gid as argument 70 Tistine6 4 find route f ncton neseser 0 Soc tea test o 71 Listing 6 5 calling the find_route function with two different gid as arguments 72 Chapter 1 Introduction 1 1 Aim The aim of this project is to research and develop an open source geographical information system that allows to find the shortest route between two points
30. ce OGCWES 1 1 p17 2 9 3 2 1 GetCapabilities A web feature service must be able to describe its capabilities Specifically it must indicate which feature types it can service and what operations are supported on each feature type p16 The request can be sent as either GET or POST request The GET request URL looks like this http hostname port path ows service WFS amp request GetCapabilities The same service can also be requested by sending the request encoded in XML in the POST body 2 9 3 2 2 DescribeFeatureType A web feature service must be able upon request to describe the structure of any feature type it can service OGCWES 1 1 p16 The response schema describes the feature types available and the operations allowed on those feature types 2 9 3 2 3 GetFeature A web feature service must be able to service a request to retrieve feature instances In addition the client should be able to specify which feature properties to fetch and should be able to constrain the query spatially and non spatially 29 2 10 Summary This project researches and integrates the components of GIS i e hardware software data procedures and people Gis data can be stored as a point lines and polygon in the spatial database Some sort of data is needed for the GIS to be useful this project uses open street map data which is free editable data for the street data which are stored as a lines buildings data which is stored as p
31. d Server BE C Processes Presentation Data Tier CH SHP2PGSQL LOADER E 4 CH ROAD SHAPE FILE Figure 1 3 Three Tier Architecture _EJ POSTGRESQL 47 POSTGIS C C 1 7 Report Overview Chapter 1 Introduction Chapter 1 provides the aim and objectives of the project It also list the glossary terms used in this project and describes the chosen development method Chapter 2 Background Chapter 2 provides background information on GIS technology its advantages in our daily life Also provides information on the specific aspects of GIS technology and standard related to the project Chapter3 Technology requirement Chapter 3 discusses and evaluate the different technologies and application needs and underlines the reason for the choosing tool to support the implementation of this project Chapter4 Shortest path algorithm Chapter 4 explains the Dijkstra shortest path routing algorithm which was chosen for this project 12 Chapter 5 Loading data setting for pgrouting and putting postgis data into geoserver Chapter 5 deals with procedures how the data was loaded and store in the database and outlines the integration between PostGIS and Geoserver This chapter focuses on how the individual components are brought together Chapter6 Code Chapter 6 Explains the code written in PL pgSQL language and OpenLayer format Chapter7 Conclusion Chapter 7 Summarizes the whole project and outli
32. e source an int identifier of the source vertex e target an int identifier of the target vertex e cost an float8 value of the edge traversal cost a negative cost will prevent the edge from being inserted in the graph e reverse_cost optional the cost for the reverse traversal of the edge This is only used when the directed and has reverse_cost parameters are true see the above remark about negative costs source_id int id of the start point directed true if the graph is directed has_reverse_cost if true the reverse_cost column of the SQL generated set of rows will be used for the cost of the traversal of the edge in the opposite direction 52 4 6 Output The function returns a set of rows There is one row for each crossed edge and an additional one containing the terminal vertex The columns of each row are pgRouting 2011 e vertex_id the identifier of source vertex of each edge There is one more row after the last edge which contains the vertex identifier of the target path e edge id the identifier of the edge crossed e cost The cost associated to the current edge It is 0 for the row after the last edge Thus the path total cost can be computated using a sum of all rows in the cost column 4 7 Query examples This query examples is based on the open street map road data named dublin_highway1 testdb SELECT FROM shortest_path testdhb SELECT gid as id testdb source integer
33. ect There were other emergent benefits that were a consequence of the planning and preparation that went into preparing this work e project management e work planning e project report making writing The following points illustrate the main learning outcomes e I ve also improved my research skills The assignments from my previous studies had given me an introduction into having to perform research to find answers For this project it was on a much grander scale By the end of the project I found that I had learned how to evaluate sources better and how to better pick the information that was relevant to my aims e Building the client side component gave the author a working understanding of the OGC s standards and specifications in general Detailed knowledge of the OGC Web 85 Map and the Simple Features was also gained through their practical application in the prototype e Data is freely available from a variety of sources The main source of data for this project was open street map data from cloudmade and the buildings are a subset of the Geodirectory from An Post originally in IGN e Becoming familiar with so many different applications and technologies has an initial steep learning curve but the knowledge attained provides a strong foundation for building similar systems in the future e Lastly I also learned a lot about the Open Source software world Previous to this project my knowledge of the open so
34. ementation of WMS plus most of the SLD extension dynamic styling Can also generate PDF SVG KML GeoRSS lt Abstract gt lt KeywordList gt lt Keyword gt WFS lt Keyword gt lt Keyword gt WMS lt Keyword gt lt Keyword gt GEOSERVER lt Keyword gt lt KeywordList gt lt OnlineResource xlink type simple xlink href http geoserver sourceforge net html index php gt lt ContactInformation gt rCOrabtrantlranam Dasme ne 4 m Figure 3 6 Result of the WMS_getCapabilities url test 3 7 OpenLayers The traditional front end technologies of HTML and CSS are used to generate content along with OpenLayers OpenLayers is an open source clientside JavaScript project that allows the connection to any OGC WMS or WFS web compliant service such as GeoServer OpenLayers According to the Hazzard 2010 openlayer allows to make interactive web maps viewable in nearly any web browser Since it is a client side library it requires no special server side software or settings it can be used without even download anything 43 3 7 1 Openlayers and web mapping OpenLayers is client side mapping library The figure below is Client Server model which is the core of how all web applications operate In the case of a web map application some sort of map client e g OpenLayers communicates with some sort of web map server e g geoserver Client Side Web Map Client Figure 3 7 Client Server Model 3 7 1 1 We
35. es PostgreSQL 8 4 share contrib routing topology sql 96 97
36. fective decision making Has great practical importance Encourage public participation in decision making Supports mapping measurement management monitoring and modeling operations for example one can combine the location of mobile workers located in real time by GPS devices in relation to customers homes located by address and derived from your customer database GIS maps this data giving dispatchers a visual tool to plan the best routes for mobile staff or send the closest worker to a customer This saves tremendous time and money GIS com Provides a challenging and stimulating educational experience for students Spatial Databases Some sort of data is needed to be GIS useful Spatial databases are such systems designed specifically to include data with spatial attributes such as geographical location distance and extent Winstanley 2009 G ting 1994 defines spatial database system as l A spatial database system is a database system 2 It offers spatial data types in its data model and query language 3 It supports spatial data types in its implementation providing at least spatial indexing and efficient algorithms for spatial join2 15 2 5 Spatial Data The fundamental ways of representing geography data in digital computers are Raster and Vector 2 5 1 Raster data Raster data as shown in the figure geography information is represented as an array of square cells Remote sensing satellite is o
37. fically their web browser EPSG DIV European Petroleum Survey Group This is the standards group for the naming of projections The two we are interested in are 4326 WGS84 and 29900 Irish Grid This is a HTML instruction for dividing the layout of a web page GIS Geography Information System GML Geographic Markup Language This is based on XML and is used to describe geographic features in respect to their location shape and height OGC Open Geospatial Consortium which is the standards body for geospatial information like web based services spatial databases OpenJump This is a Java based product for exploring spatial information OWS OGC web service URL Uniform Resource Locator WES Web Feature Service This is a service given by a Map Server to return features in GML and also allow transactions WFS T on the feature WKB Well Known Binary This is how a database often stores a geographic feature in the database WMS Web Map Service This is a service provided by the Map Server to return map images to the client for a specified area and sometimes conditions using filtering Table 1 1 List of Glossary items 1 4 Methodology This project involves only one resource me however traditional life cycle models requires many specialist So iterative style approach i e prototype method would be suitable for this project where all the requirements are defined then de
38. followed by the name of a database to connect to Mitchell 2005 When psq start up tells the version of the program gives few lines of helpful tips to start the program and then leaves with the prompt the prompt is the name of the database followed by postgres 5c postgis peql 8 4 25 WARNING Console code page 437 differs from Windows code page 1252 gt 88 bit characters might not work correctly See psql reference page Notes for Windows users for details You are now connected to database postgis Listing 3 2 Verfying PostGIS functionality ostgis H select postgis_versionC postgis_version 1 4 USE_GEOS 1 USE_PROJ 1 USE_STATS 1 Ci row Listing 3 3 Showing the version of PostGIS The output tells the version of PostGIS being used is 1 4 and also shows that it can use GEOS and PROJ libraries as part of PostGIS Proj libraries are used to reproject or transform coordinates and GEOS is an advanced geometry engine that allows a whole suit of manipulations and analysis of geometry data types Mitchell 2005 3 3 1 Standard Compliance PostGIS PostgreSQL was the first open source database to support OGC compliant spatial SQL PostGIS supports many of the OGC ISO SQL MM compliant spatial 34 functions you will find in these other OGC compliant databases as well as numerous additional ones that are unique to PostGIS 3 3 OpenJump OpenJUMP is an open source Geographic Information System GIS written in
39. ft com en US windows7 products home Accessed July 21 2011 Mitchell T 2005 Web mapping illustrated Google Books Available at http books google com books hl en amp lr amp id IdGoy2rZSyIC amp oi fnd amp pg PR3 amp dq web mapping amp ots to VZFMkbMN amp sig kuqnTOEeCPBpSSXKnjNSDVX 64RQ v onepage amp q amp f false Accessed August 1 2011 Hazzard E 2011 Openlayers 2 10 Beginners Guide Packt publishing Mozilla Mozilla com Mobile Available at http www mozilla com en US m faq Accessed August 13 2011 OGCWMS 1 3 Web Map Service OGC R Available at http www opengeospatial org standards wms Accessed August 3 2011 GeoServer 2011 Welcome GeoServer Available at http geoserver org display GEOS Welcome Accessed August 2 2011 WSA 2004 Web Services Architecture Available at http www w3 org TR ws arch Accessed August 2 2011 OGC 2002 Web Map Service Implementation Specification Available at http cite opengeospatial org OGCTestData wms 1 1 1 spec wms1 1 1 html Accessed August 2 2011 Deoliveira J GeoServer Uniting the GeoWeb and Spatial Data Infrastructures 89 http www gsdi org gsdiconf gsdil 0 papers TS26 4paper pdf OGCWES 1 1 0 2005 Web Feature Service OGC R Available at http www opengeospatial org standards wfs Accessed August 7 2011 OSM 201 1a OpenStreetMap Available at http www openstreetmap org Accessed July 28 2011 Haklay M amp
40. function find nearest _road function is assigned as a variables within this function Line 17 to 27 return query returns out value of the function through Dijkstra shortest path core function source and target ids are vertex ids source and target is cast into integer and length to double precision s and f is passed as variable which came from declaration section false false means has reverse cost is set to false After calling this function find_nearest_road in psql shell got the shortest path between the two buildings with gid 1375 and 59 testdb select from find_route 1375 59 gt columni column2 i column3 A ARRAS 12348 i 8059 i 249 7375B4252945 12654 i 8286 i 219 425248673462 12992 i 8613 i 123 671322795878 13192 i 8699 i 55 2261869618148 13433 8734 i 166 426985819356 433 1 i i a lt 6 rows Listing 6 5 calling the find_route function with two different gid as arguments e Then the view was created to see the shortest path between buildings with gid 1375 and 59 Listing below shows how the view was created in psql shell 72 testdb CREATE OR REPLACE WIEW route AS lt testdbt SELECT FROM shortest_path testdb SELECT gid as id testdh source integer testdh target integer testdb length double precision as cost testdh FROM dublin_highwayl 12548 433 false false gt gt CREATE WIEW da IL aH
41. herefore telling the web browser to run this function at the same time as the webpage body is loaded gt function init creates a new openlayers Bounds object Bound sets the geographic limit of the display layer var bounds new OpenLayers Bounds 297730 375 217955 328 330136 625 260578 453 In this example we set some custom map options First we set controls new OpenLayers Control PanZoom Next the map units to m for meters was set and projection was set in 29900 Irish national grid var options controls new OpenLayers Control PanZoom maxExtent bounds maxResolution 166 49658203 125 projection EPSG 29900 units m The OpenLayers Layer WMS constructor requires 3 arguments and an optional fourth dublin new OpenLayers Layer WMS dublin historical http localhost 8080 geoserver wms layers Ireland buildings_geodir transparent true 75 The first argument dublin is a string name for the layer This is only used by components that display layer names like a layer switcher and can be anything of choosing The second argument http localhost 8080 geoserver wms is the string URL for a Web Map Service The third argument layers Ireland buildings_geodir is an object literal with properties that become parameters in our WMS request In this case we re requesting images rendered from a single layer identified by the name Trela
42. http localhost 8080 geoserver web hitpy locathost8060 geoserver web prominent examples of web map se w EJ Search ug Page Status ES News 5 CI email S 15 c E Geoserver Welcome About amp Status Welcome amp About GeoServer This GeoServer belongs to The ancient geographes INC Service Capabilities Data 18 GeoServer instance amp runnin BD Layer Proview E Demos Figure 3 2 The Geoserver Web Admin Tool To run some of the sample requests that can be used to test the installation the Geoserver demo page was loaded http localhost 8080 geoserver web wicket bookmarkablePage 0rg geoserver web De moPage 39 GeoServer Demo requests Example requests for GeoServer using the TestServlet Select a request from the request url and body if an xml request Hit submit to send the request to GeoSen About amp Status 8 About GeoServer Data Layer Preview Request WFS eT ET WFS_getF eatureFid url WFS_getF eatureFidFilter url WFS_getFeaturelntersects 1 0 xml WFS_getFeaturelntersects 1 1 xml WFS_getFeaturelntersects url WFS_getFeatureMultiFilter url WFS_mathGetFeature url WFS_mathGetF eature xml WFS_transactionDelete xml WFS_transactionInsertxml WFS_transactionUpdate xml WFS_transactionUpdateGeom xml WMS_GetLegendGraphic SLD url WMS_GetLegendGraphic SLD_BODY url WMS_GetLegendGraphic url WMS_describeLayer url WMS_feature
43. i character varying S i type character varying lt i3 gt i name character varying 34 i oneway character varying lt 4 gt the_geom i geometry i Indexes dublin_highwayl_pkey PRIMARY KEY btree Cgid Check constraints enforce_dims_the_geom CHECK lt st_ndims lt the_geom gt 2 enforce_geotype_the_geom CHECK lt geometrytypelthe_geom gt MULTILINESTRING text OR the_geom IS NULL gt enforce_srid_the_geom CHECK lt st_srid the_geom gt 29988 Listing 5 2 Verifying successful data imports to postgis Listing 5 2 shows the attributes in the dublin highway1 table Each column is listed and shows the datatype that each column can hold PostgreSQL database can handle all these types without PostGIS except for the geometry data Only one column in the table contains geometry data and can be seen in the listing that it is of type MULTLINESTRING geometry the the_geom column has geometry listed as its type The_geom geometry The network data dublin highway provides the following information e Road link id gid e Road type for ex primary secondary tertiary e Road name name e Road geometry the_geom 57 However this data allows to display the road data as a PostGIS layer for example in openJump which I am using for this project But for the routing function to work the network data should contain a network topology information The steps for creating network topology is explained in section 5 2
44. i e buildings Find route from one building to another building using PostgreSQL PostGIS initally display result in OpenJump Key to achieving this aim is the successful integration of database technology a GIS server and front end web technology to display information to the end user through a browser 1 2 Objectives By choosing my main objective was to e Research install and configure a spatial database e Research install and configure client that act as gis viewer to perform analysis of datasets query the database Research install and configure software to act as the client interface in conjuction with the user s browser Research install and configure coding language that interact with spatial database Acquire competency using the tool OpenJump PostgreSql and GeoServer To acquire the data which will be used for the route finding To load the database with valid data To design the systems that integrates all the components To create a queries that will allow the user to initially interact with the data in OpenJump To create an interface that allows the user to interact with the system 1 3 Glossary AJAX Asynchronous JavaScript and XML Bounding Box This is a rectangle that is used to identify the Clients area we are interested in whether that is finding geometries in a database or telling a map server the area of the map we wish to see ide Client side referrs to the user s computer speci
45. ish National Grid IGN The buildings are a subset of the Geodirectory from An Post originally in IGN The road data and buildings data are loaded to postgresql using psql SQL terminal monitor Postgis manual from the command prompt psql d testdb U postgres f dublin_highwayl sql psql d testdb U postgres f buildings_geodir sql d name of the database U user 55 The username to use when connecting to database f file name The table named buildings geodir contains the following attributes ttestdb Md buildings_geodir Table public buildings_geodir Column i Type Modifiers C q _ Ay _ gt _ A _ _ _ _ Q E gid integer i not null default nextval buildings _geodir gid_seq regclass gt building_i bigint group_id bigint bigint bigint bigint thorfare_i post_town_ data_src_i changed_da character varying 8 gt presort_id bigint postaim_id bigint ed_id bigint name character varying 4 gt no character varying 4 gt building_u character varying 1 gt derelict character varying 1 gt 1 1 e H H H H H H H 1 1 H H H 1 1 i vacant i character varying 1 gt L i i i i i i i i i i 1 1 invalid character varying 1 gt under_cons character varying 1 gt residentia bigint commercial bigin
46. ive specification documents function in similar ways Both services provide public interfaces through which clients can request information about the feature types and the operations on those feature types that it stores and both services respond to those requests with XML documents 24 The communication between client and server is achieved via the HTTP protocol over a heterogenous network such as the World Wide Web HTTP supports both GET or POST methods OGC 2002 Both services have a GetCapabilities request that provides service level information available about the WMS WES In a GET request the service that the client requires is specified through key value pairs K VPs in the URL of the request In a POST request the content of the request is encoded in XML and passed to the server through the POST BODY of the request header 2 9 3 1 Web map Service WMS WMS is a standard for displaying map images WMS can register and overlay maps from multiple remote sources A map is not the data itself WMS produced maps are generally rendered in a pictorial format such as PNG GIF or JPEG or occasionally as vector based graphical elements in Scalable Vector Graphics SVG or Web Computer Graphics Metafile WebCGM formats OGCWMS 1 3 0 p5 WMS is fine for presentation and a delivery mechanism but not good for user interaction The OGC Web Map Service Standard supports the 3 following basic interfaces GetCapabilities GetMap and GetFeatu
47. licked on publish for dublin_highway1 Then it returned detailed layer information for the dublin_highway1 table layer Coordinate Reference Systems Native SRS EPSG 29900 EPSG TM6S Irish National Grid Declared SRS EPSG 29900 EPSG TM6S Irish National Grid SRS handling Force declared Bounding Boxes Native Bounding Box Min X Min Y Max X Max Y 297 730 375 217 955 328 330 136 625 260 578 453 Compute from data Lat Lon Bounding Box Min X Min Y Max X Max Y 6 538 53 196 6 036 53 586 Compute from native bounds Figure 5 6 Computing bounding boxes in Irish National Grid Figure 5 6 shows system computing the bounding boxes by clicking on Computer from data and Compute from native bounds When clicked Save got Layers Manage the layers being published by GeoServer Add a new resource Remove selected resources Results 1 to 1 out of 1 matches from 21 items mu Ireland dublin_highway1 dublin_highway 1 Y EPSG 29900 4 Results 1 to 1 out of 1 matches from 21 items Figure 5 7 Result after the coordinate system was set to Irish National Grid 29900 66 Again the step3 and step4 was repeated to add the buildings data to GeoServer but this time Data Source name is buildings geodir Step5 Add a layer group This step was done to display the road table and buildings table together ss New Layer Group Add a new layer grouping O highwaybuildings Bounds Min X Min Y Max X
48. llows to directly use the SQL language from within PL pgSQL code PostgreSQL 2011 PL pgSQL was chosen as because multiple SQL statements can be executed from a PL pgSQL code block the statements are processed at one time instead of the normal behavior of processing a single statement at a time as a result this increases the power flexibility and performance of the program 37 Another important aspect of using PL pgSQL is its portability it is platform independent its functions are compatible with all platforms that can operate the PostgreSQL database system Disadvantage is that inserting function in the database doesn t guarantee that function can be called Geschwinde amp Sch nig 2001 3 6 Firefox Mozilla Firefox is the open source web browser developed by Mozilla Corporation and was the browser of choice during development of the prototype Firefox was downloaded from http getfirefox com uses the Gecko layout engine to render XHTML markup and CSS is currently the most W3C open standards compliant browser Mozilla com Many extensions are available in firefox to enhance its capabilities firebug version 1 7 3 was downloaded from http getfirebug com Firebug as an addon on firefox makes the web development process much easier and quicker With these tools anything on the site can be change on the fly without editing or saving any files So firebug provides an invaluable aid by providing developer level debug tools
49. lnfo url Demos URL Body WMS_getMap url Figure 3 3 The GeoServer Demo page The three tests to run are the tests that correspond with the three web map operations that were researched and discussed in chapter 2 The tests are WMS_getMap url WMS_getCapabilities url WMS_featureinfo url 40 Test WMS_getMap url After choosing the WMS_getMap url test and hitting submit the following result displayed TestWfsPost PNG Image 550x250 pixels Figure 3 4 Result of the WMS_getMap url test Test WMS featureinfo url 41 Results for FeatureType states GEOMETRY MultiPolygon with 153 points E Arizona STATE FIPS 04 SUB_REGION Mtn STATE ABBR AZ LAND KM 294333 462 WATER KM 942 772 PERSONS 3665228 0 FAMILIES 940106 0 HOUSHOLD 1368843 0 MALE 1810691 0 FEMALE 1854537 0 WORKERS 1358263 0 DRVALONE 1178320 0 CARPOOL 239083 0 PUBTRANS 32856 0 EMPLOYED 1603896 0 UNEMPLOY 123902 0 SERVICE 455896 0 MANUAL 185109 0 P MALE 0 494 P_ FEMALE 0 506 SAMP_POP 468178 0 Figure 3 5 Result of the WMS_getCapabilities url test 42 lt WMS Capabilities version 1 3 0 updateSequence 108 E xsi schemalLocation http www opengis net wms http localhost 8080 geoserver schemas wms 1 3 0 capabilities 1 3 0xsd gt lt Service gt lt Name gt WMS lt Name gt lt Title gt GeoServer Web Map Service lt Title gt lt Abstract gt A compliant impl
50. lt script src openlayers OpenLayers js gt lt script gt This includes the OpenLayers library The location of the file is specified by the src openlayers OpenLayers js attribute Here I am using a relative path As the index html page is in the same folder as the OpenLayers js file An absolute path can also be used that is it can be pass in a URL that the script is located at OpenLayers org hosts the script file as well the following line of code can be used to link to the library file directly lt script type text javascirpt src http openlayers org api OpenLayers js gt lt script gt The advantage of using absolute path is that you do not need to maintain a local copy of the JavaScript library on your own web server ensuring that you always have the most up to date product on offer The disadvantage of this is that you must always have internet connectivity to access their functionality So I have chosen to use the localcopy for this project lt script gt starts a block where all our code is set up inside it to create map var map global variable called map is created In JavaScript anytime a variable is created it is needed to place var in front of it to ensure that we don t run into scope issues what 74 functions can access which variables When accessing a variable no need to put var in front of it lt init used to initialize the map using the onload init in the body of the HTML page t
51. m developed by Dutch computer scientist Edsger Dijkstra in 1959 is often used in routing It is a graph search algorithm that solves the single source shortest path problem for a graph with non negative edge path costs outputting a shortest path tree Sutskever 2008 A path from a source vertex v to a target vertex u is said to be the shortest path if its total cost is minimum among all v to u paths Dijkstra s algorithm is based on the following assumptions Chen 2003 e All edge costs are non negative e The number of vertices is finite e The source is a single vertex but the target may be all other vertices 4 2 Principle of the algorithm The graph is made of two entities vertices or nodes and edges which link vertices together Edges are directed and have an associated distance sometimes called the weight or the cost The distance between the vertex u and the vertex v is noted u v which is shown in figure 3 1and is always positive Renaud Waldura 2007 Dijkstra s algorithm defines vertices in two distinct sets the set of unsettled vertices and the set of settled vertices A vertex is considered settled and moved from the unsettled set to the settled set once its shortest distance from the source has been found Initially all vertices are unsettled and the algorithm ends once all vertices are in the settled set u v 5 v w 3 eo v u 2 Figure 4 1 Dijkstra shortest path algorithm example 46 4 3 E
52. mpound unique partial and functional indexes which can use any of its B tree R tree hash or GiST storage methods This project makes use of procedural language feature of PostgreSQL and PL pgSQL language was selected which installs by default within PostgreSQL 3 3 PostGIS PostGIS is the most powerful open source spatial database which spatially enables the PostgreSQL open source relational database management system Obe amp Hsu 2010 PostGIS is an extension to the PostgreSQL object relational database system which allows Geographic Information Systems objects to be stored in the database PostGIS includes support for GiST based R Tree spatial indexes and functions for analysis and processing of GIS objects PostGIS It adds to PostgreSQL several spatial data types and over 300 functions for working with these spatial types geometry geography types packaged in Microsoft SQL Server 2008 do for SQL Server PostGis was installed for this project to stored the spatial data such that it was possible to do interaction from openjump openlayer and server i e geoserver which was used through test face to implementation phase of this project 33 3 3 1 Testing PostGIS functionality Some simple tests can be done to connect to the postgis database using psql command The psql command lists the databases and runs scripts and also provides an interface for typing in SQL commands and shows query results This is done by starting psql
53. nd buildings_geodir add layers to the map can be done together but here I have done it separetly map addLayer counties map addLayer dublin map addLayer start map addLayer stop support GetFeatureInfo lt Capture mouse events and pass request to function to be execute so that an user can click on the map to get map information of the area of interest gt map events register click map function e define the result of getfeatureInfo the parameters are listed below var params REQUEST GetFeatureInfo EXCEPTIONS application vnd ogc se_xml BBOX map getExtent toBBOX X Xy X 76 Y e xy y INFO FORMAT text html get map query retrieve information from the database QUERY _LAYERS Ireland dublin_highway1 buildings geodir set maximum number of return feature FEATURE COUNT 5 LAYERS Ireland dublin_highway1 buildings geodir Styles set Irish coordinate Srs EPSG 29900 WIDTH map size w HEIGHT map size h format format Tf you activate a radio buttion eg for the startpoint the function toggleControl is activated lt input type radio name control value start id startToggle onclick toggleControl this gt lt label for startToggle gt set start point lt label gt draw feature control is created this creates an OpenLayers Control DrawFeature control We construct this layer with an OpenLayers Handler Point to allow drawing of point
54. ne of most common form of raster which capture information in raster form Longley et al 2010 A raster data associates attributes with grid cells 2 5 2 Vector data Vector data as shown in the figure is a coordinate based data model which represents geographic features as points lines and polygons Each point feature is represented as a single coordinate pair while line and polygon features are represented as ordered lists of vertices ESRI 2011b This project makes a use of vector data raster data urban area river vector data Figure 2 2 Raster and vector 16 2 6 Spatial join A spatial join is done between road and buildings table dataset used in this project with respect to a spatial predicate A spatial join links two or more tables based on a spatial relationship rather than the classic non spatial relational attribute Lecture2 2011 Predicates can be a combination of directional distance and topological spatial relations e g overlap contains In case of non spatial join the joining attributes must of the same type but for spatial join they can be of different types Lecture2 2011 Example Query For all the rivers listed in the River table find the counties through which they pass SELECT r name r name FROM river AS r county AS c WHERE crosses r the_geom c the_geom True The spatial predicate Cross is used to join River and Country tables 2 7 OpenStreetMap OpenStreetMap data
55. nes the learning outcomes the benefit the application and further work 2 Research Areas This chapter presents the research areas that were crucial for this project It begins by describing what geographic information system is and those elements that makes the GIS possible It also point outs the various standards of Open Geospatial Consortium and their relevance to the web mapping services 2 1 Geographic Information Systems Geographic Information Systems is neither a single thing nor a single analysis ISS 2006 the primary thing that makes GIS difference is location the place where almost everything that happens happens somewhere Longley et al 2010 Whether it s the regular delivery of morning newspaper the synchronization of traffic lights on way to work or the convenient location of favorite park GIS make these things happen ESRI 201 1a so GIS is a computerized tool for solving geographic problems Longley et al 2010 p 16 In today s 21 century organizations all over the world are using GIS to manage the environment work more efficiently provide better customer service and save money A geographic information system GIS is the integration of hardware software and data for capturing managing analyzing and displaying all forms of geographically referenced information GIS com 2011 13 Many historians and historical geographers regard GIS as primarily being concerned with mapping Although mapping
56. o a Kingfisher Ch W E The Blue Blazer o _Main Bread Street E a a A Al A Y EN A 5 P NA lt Le Figure 2 3 The Blue Blazer represented as node Bennett 2010 2 7 1 2 Ways Ways are ordered list of nodes which represents a polyline or polygon such as roads paths and waterways Bennett 2010 They can also be closed to form areas Where 18 they re used to describe linear features the way should normally be placed down the center line of the physical feature and at the perimeter for an area Figure 2 5 shows the way which is the southern end of Parliament Street in London Figure 2 4 Parliament Street in London represented as way Bennett 2010 2 7 1 3 Relations Relations are groups of nodes ways and other relations which can be assigned certain properties Bennett 2010 Relations allow mappers to model features that can t be described using a single node or way or where two of the same type of feature overlap Examples include complex branching streets long distance routes or the turn restrictions at junctions 2 8 Web services W3C Web Services architecture WSA 2004 specification defines a web service technically as follows A Web service is a software system designed to support interoperable machine to machine interaction over a network It has an interface described in a machine processable format specifically WSDL Other systems interact with the Web
57. oints Processing geographic data was originally only available through desktop applications but now is available over the Internet either via client server interaction This project is based on both desktop and client server model 30 3 System setup There is no definitive set of components to use when creating a GIS This chapter details the system that has been chosen for this project 3 1 Hardware All applications are installed on a single machine in this case an HP laptop running Windows 7 which has the following specifications Windows 7 CPU 2 20 GHz RAM 4 00 GB 31 Operating System Windows 7 Table 3 1 Hardware 3 2 Software Table 3 2 shows the main list of the software chosen for this project Version Function PostgreSQL 8 4 Database Postgis 1 4 Database pgRouting 1 0 3 Routing OpenJump 1 3 1 Client desktop gis Geoserver 2 1 0 Mapserver Openlayers 2 8 Web client front end Firefox 5 0 Web browser PL pgSQL Procedural language Table 3 2 Software Applications used in system 3 2 1 PostgreSQL PostgreSQL is a powerful open source object relational database system which has more than 15 years of active development and a proven architecture because of its strong reputation for reliability data integrity and correctness PostgreSQL 1996 2010 PostgreSQL with the spatial addon PostGIS was chosen as the author has previous experience
58. ollowing SQL command populates the length field which will be used as the edge cost in the network topology UPDATE dublin_highwayl SET length length the_geom Test the lengths have been calculated estdb select lengthtthe_geom gt from dublin_highvayi length 8065 43884257229 399 760888836039 122 317192867977 14 1015912173981 Listing 5 7 Verifying the lengths column has updated successfully 5 2 1 Add indices Adding indices speeds up the data access so it improves the query performance This is done using the CREATE INDEX command The command to create an index for the geometry in the dublin_highway table looks like this CREATE INDEX source idx ON dublin highwayl source CREATE INDEX target idx ON dublin highwayl target CREATE INDEX geom idx ON dublin highwayl USING GIST the geom GIST _GEOMETRY OPS Listing 5 8 Command to create index for the geometry The source_idx target_idx and geom idx is used for the name of the index The second parameter dublin highway is the name of the table for which indexes are being created The field that hold geometry data is identified as the_geom The rest of the command consists of keywords needed for indexing functions to run and must be used as shown Mitchell 2005 60 5 3 Example of Spatial SQL queries ostgis select sum ST_Lengtht the_geom gt gt 1808 As km_roads FROM dublin_highway1 km_roads 4337 86288135471 Ci row This spatial que
59. om one name place to another e Create a web service where the routing algorithm runs on the web server and accepts queries from web clients The server performs all required computations and generates images with recommended routes that are sent back to the client e Create route based on more than one routing algorithms 87 8 References GeoServer 2009 Web Administration Interface GeoServer 2 1 0 User Manual Available at http docs geoserver org 2 1 0 user webadmin index html Accessed August 11 2011 Chen C J Dijkstra s Shortest Path Algorithm JOURNAL OF FORMALIZED MATHEMATICS Volume 15 Released 2003 Published 2003 Inst of Computer Science Univ of Bialystok pgRouting 2011 Shortest Path Dijkstra Open Source Routing Library Available at http www pgrouting org docs l x dijkstra html Accessed July 18 2011 Sutskever V 2008 Dijkstra Algorithm implementation in Java Available at http www cs nyu edu vs667 development DijkstraAlgorithm Accessed July 18 2011 Waldura R 2007 Dijkstra s Shortest Path Algorithm in Java Available at http renaud waldura com doc java dijkstra Accessed July 18 2011 Lecture 6 2011 spatial databases lectures Available at http www comp dit ie pbrowne Spatial 20Databases 20SDEV4005 Spatial 2 0Databases 20SDEV4005 htm Accessed July 18 2011 RUMBAUGH J JACOBSON I and BOOCH G 1999 The Unified Modeling Language Reference Manual Reading Mass
60. ometries for existing features openlayer uses event listener to handle the mouse events var SinglePoint OpenLayers Class create SinglePoint prototype OpenLayers Class inherit OpenLayers Handler Point createFeature function evt this control layer removeFeatures this control layer features OpenLayers Handler Point prototype createFeature apply this arguments D Finally behavior was added to the lt input gt element in order to activate and deactivate the draw control when the user clicks the checkbox We ll also call the toggle function when the page loads to synchronize the checkbox and control states Add the following to your map initialization code function toggleControl element for key in controls if element value key amp amp element checked controls key activate else controls key deactivate j 79 In order that users can also navigate with the mouse we don t want this control to be active all the time We need to add some elements to the page that will allow for control activation and deactivation In the lt body gt of your document add the following markup lt input type radio name control id noneToggle onclick toggleControl this checked checked gt lt label for noneToggle gt navigate lt label gt Finally figure below shows the two tables dublin highway and buildings geodir displayed as a layer through openlayers AN EA A aa
61. operations associated with it Purchase et al 2001 Here the class diagram are represented with boxes which contain three parts e The upper part holds the name of the class e The middle part contains the attributes of the class e The bottom part gives the methods or operations the class can take or undertake INFINITY Integer node GraphNode cost Integer lt lt creale gt gt Edge nodeTo GraphNode cost integer getNodef GraphNode getCostd Integer Dijkstra graph Graph pini A GraphNndePriortyQueue GrapnNodePriontyQueue distance Hashtable z pQueue PriorityQueue lt lt creale gt gt Dijkstra g Graph 900 void lt lt creale gt gt GraphNodePriorityQueue PrintStatusOfPriortyQQ void addin GraphNode void add nodeCollecti on Colection void TestDikstra hasMore Boolean removed GraphNode updateGraphNodeDistance n GraphNode void mabh aras Strinal void PrintConterts void p s String void Figure 4 7 a UML for Dijkstra s shortest path algorithm Lecture 6 2011 50 nodeCourt int oulGongEdges ArrayList val String ID integer visited boolean distance Integer lt lt create gt gt GraphNode value String lt lt creale gt gt GraphNoded inii nodeV al String void printo void selvisted visted boolean void AddO ulgoingEdge node GraphNode cost Integer void getOutGoingEdges ArrayList getVald String sefVal
62. programming language was used to put the queries together By using this language first the small function named as find nearest road was created and this function was passed as a variable in another function named find route which is described in section 6 1 2 6 1 1 find_nearest_road function CREATE OR REPLACE FUNCTION find nearest_road gid int out nearest_road int 2 AS 5 dollar quoting approach DECLARE El BEGIN EJnearest_road select h source from dublin highwayl as h buildings geodir as b where pb gid gid and contains buffer h the geom 30 b the_geom order by source LIMIT 1 end of the block structure END LANGUAGE plpgsql Listing 6 1 find_nearest_road function Line 1 Creates the function named find nearest road and states its argument gid as integer and states the OUT parameter named nearest road of type integer This OUT parameter allows to return outputs from a function without having to declare a PostgreSQL type as output of the function In Line 3 the dollar sign represents the dollar quoting approach Dollar quoting approach is used beacause CREATE FUNCTION call that creates the PL pgSQL function is specified as a string literal If the string literal is written in ordinary way with single 69 quotes then any single quotes inside the function body must be doubled likewise any backslashes must be doubled In dollar quoting approach there is no need to double any quote marks
63. relInfo 2 9 3 1 1 GetCapabilities GetCapabilities is a request from a client to a service that gives back the capabilities or services that this service provides for maps OGCWMS1 3 p21 This is an XML document that gives the metadata of the information available The metadata is readable by a machine and the human eye and contains a description of the server s information content and the acceptable request parameter values Listed below are the possible parameters of aGetCapabilties request 25 Mandatory aah as Dc Optional SERVICE WMS Service type REQUEST GetCapabilities Request name FORMAT MIME_type Output format of service metadata UPDATESEQUENCE string Sequence number or string for cache control Table 2 1 The parameters of a GetCapabilities request OGCWMS1 3 p21 The GetCapabilities response is an XML document which contains the service metadata The metadata will appear in a human readable format in the client application In the case of this work that is a web browser OGCWMS1 3 p22 The contents of the metadata that is returned can include e Service information such as a name title URL and other optional information such as contact information fees access constraints e Capability information which lists the operations supported by the server their output formats and also the URL prefix for each of these operations e Layers and styles metadata which outlines the layers and styles that are
64. rview of objectives Objective Deliverables Research install and configure a spatial PostGIS database Research install and configure coding PL pgSQL language that interact with spatial database Acquire competency using the tool OpenJump PostgreSql and GeoServer These tools were successfully downloaded and integrated Research install and configure software to act as the client interface in conjuction with the user s browser openLayers Research install and configure client that act as gis viewer to perform analysis of datasets query the database OpenJump 84 To acquire the data which will be used for the route finding The streets use OSM data from CloudMade The OSM data was transformed to Irish National Grid IGN The buildings are a subset of the Geodirectory from An Post originally in IGN To load the database with valid data Database was loaded with both data i e street data and buildings data To design the systems that integrates all the components Integrated system is designed in chapter 5 To create a queries that will allow the user to initially interact with the data in GIS client To create an interface that allows the user to interact with the system OpenJump Only the part of the interface was designed Using HTML CSS OpenLayers and Geoserver Table 7 1 Objectives and their corresponding Deliverables of the proj
65. ry is selecting the total length of the roads in dublin highway1 table expressed in kilometres ostgis select count gt from buildings_geodir count 3626 Ci row This query reports the number of features in the buildings _geodir table estdb SELECT count lt distinct gid FROM buildings_geodir count This query counts the total number of distinct buildings in buildings geodir table estdb SELECT r name FROM dublin_highwayl1 as r buildings_geodir as b WHERE b gid 1375 and containsChbuffertr the_geom 30 gt b the_geom gt name Kevin Street Lower lt 1 row This query is selecting the road name in dublin highway1 table which is within 30 m distance from the buildings with gid 1375 in buildings geodir table So two table are joined together pair at time using topology and set comparison operator contains and spatial analysis operator buffer 61 estdb select source from dublin_highwayi where name Kevin Street Lower source 12348 lt 1 row This query is selecting the source of the road named Kevin Street Lower in dublin highway1 table estdb select source from dublin_highvayi where name Mercer Street 5 source This query is selecting the source of the road name Mercer Street in dublin highway1 table which returns three source as an output 5 4 Putting PostGIS data into Geoserver There is a certain order to which data must be loaded to GeoServer First a
66. shapefile or a directory such as Vector Product Format library The store construct is used so that connection parameters are defined once rather than for each piece of data in a source As such it is necessary to register a store before loading any data Select Stores New data source PostGIS then the form was filled out as follows New Vector Data Source Add a new vector data source PostGIS PostGIS Database Basic Store Info Workspace Ireland Data Source Name dublin _highway 1 Description V Enabled Connection Parameters host localhost port 5432 database testdb schema public user postgres passwd le Namespace http www openplans org sushma Listing 5 9 Filling out the form for the new data source 64 On Saving was presented with a list of all the tables in the test db database New Layer Add a new layer You can create a new feature type by manually configuring the attribute names and types Create new feature type On databases you can also create a new feature type by configuring a native SQL statement Configure new SQL view Here is a list of resources contained in the store dublin_highay1 Click on the layer you wish to configure lt 2 gt gt gt Results 1 to 18 out of 18 tems f i ii F 4 E i A AA EEES E f i 3 E Figure 5 5 Layer view Step 4 Publish C
67. sign the system and then implement rather then developed the whole product and move to the another area that is not well known 10 1 5 Project Management Project management is very important activity that overlaps many phases of system methodology According to Whitten et al 2001 project management is the process of defining planning directing monitoring and controlling a project to develop a system within allocated time and budget Figure 1 1 is the gantt chart showing the project plan to be followed a GANTT x ee 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 Septer Duration 5 e b ho m pa ha ha fs he fe ho Jo pi p2 3 as s j pr ps fs fo fi kb ps fa ps ps Figure 1 1 Gantt chart showing the project plan Name Duration Routing using open source software 152 Research 32 Software 18 Install amp test software 4 Design 22 Complete IPR 21 Implementation 43 Project Report 44 Deliver 1 Presentation 3 Figure 1 2 Listing of the task name and duration from Gantt Chart 1 6 Overview of the architecture used The diagram below illustrates the different components needs to build the system and the interaction between them Each of these and their installation and usage will be discussed later in document 11 4 WEB BROWSER E H ROUTING INTERFACE al OPENS VER AA Middle Tier C7 OPENJUMP gt 7 GEOSERVER Analysis an
68. such as the JavaScript and CSS live edit feature and the ability to troubleshoot the HTTP request and response headers when working with Geoserver for this project 3 7 GeoServer 2 1 0 GeoServer is an Java Enterprise Edition open source software server Java that allows users to share and edit geospatial data Geoserver 2 1 0 GeoServer is Open Geospatial Consortium OGC Web Feature Service WFS and Web Coverage Service WCS standards as well as a high performance certified compliant Web Map Service WMS Windows Installer version of GeoServer geoserver 2 1 0 ng exe was downloaded from http geoserver org display GEOS GeoServer 2 1 0 and set up manually Users can create maps in a variety of output formats as OpenLayers which is an integrated part of its structure map generator will be quick and easy and will be easy to establish connection with traditional GIS architectures It easy to install and to use it supported by many OS platform and have great document 38 support on his website make it the perfect open source web map sever to use It also has a constraint for implementing extra feature on a standalone earth client as user will have to know java scripting language to programmatically control it 3 6 1 Testing Geoserver At first need to start GeoServer by going to the Start Menu and clicking Start GeoServer in the GeoServer folder Then to load the Geoserver web admin tool the following URL is used
69. t county_id bigint tland_id bigint east numeric north numeric locality_i bigint secondary_ bigint verified character varying 1 gt itm_east numeric itm_north numeric quality_co character varying 15 gt create_dat character varying 8 gt the_geom geometry Indexes buildings_geodir_pkey PRIMARY KEY btree gid gt heck constraints enforce_dims_the_geom CHECK lt st_ndimstthe_geom gt 2 gt enforce_geotype_the_geom CHECK lt geometrytype the_geom gt POINT text OR he_geom IS NULL gt enforce_srid_the_geom CHECK lt st_srid the_geom gt 2998 gt Listing 5 1 Verifying successful data imports to postgis Listing 5 1 shows the attributes in the buildings geodir table Each column is listed and shows the datatype that each column can hold PostgreSQL database can handle all these types without PostGIS except for the geometry data Only one column in the table contains geometry data and can be seen in the listing that it is of type point geometry the the _geom column has geometry listed as its type The_geom geometry 56 The table named dublin highway containing road network data has the following attributes postgis Sd dublin_highway1 Table public dublin_highwayi Column i T ype Modifiers F elo A AA A A A A R gid i integer i not null default nextval dublin_highwayl Sid seg pupa Sgid bigint i gid character varyingt5 gt i gid character varying 5 gt i o gid
70. t chart showing the project plad ooooonnccnincnionccnccnconnconncconacanc cono nonnnonns 11 Figure 1 2 Listing of the task name and duration from Gantt Chal t oooconnconncnocinoninccnancns 11 Fig r 1 3 TA ta de 12 Figure 2 1 Parts Of Gis Longely 200 ias AA a 15 Figure 2 27 Raster and VELO AAA A ia A 16 Figure 2 3 The Blue Blazer represented as node Bennett 2010 0 oooonccciccncccocccoccconcnonons 18 Figure 2 4 Parliament Street in London represented as way Bennett 2010 19 Figure 2 5 OpenGIS Geometry Class Hierarchies OGCSFS 1 1 p2 2 cece 22 Figure 2 6 Schema for feature tables under SQL92 OGCSFS1 1 p2 20 wo 23 Figure 2 7 The OGC web service architecture OWS 2002 oooooiccinocinococoncconcnonnnonnnonns 24 Figure 3 1 Openjump user interface risa 36 Figure 3 2 The Geoserver Web Admin Tool ooooonncnnncniccnocanocconanoncnononnnonncnncnccnnnonncnnnons 39 Figure 3 3 The GeoServer Demo PARE dada 40 Figure 3 4 Result of the WMS getMap url test cc cecccsscseceeseeeeeceeeeeeeeeeeeesaeenes 41 Figure 4 1 Dijkstra shortest path algorithm example ococonconcnnncinconocnonncononononononnccnnanns 46 Figure 4 2 Initialisation in Dijkstra shortest path algorithm with source vertex a 47 a A E E 48 ia A aces o iaa a i a e 48 Figure 4 5 Third Iteration do 49 Figure 4 6 Fourth Iteratiots seinere eis au senses a tiee ea Aa e ea aa E ames iit 49 Figure 4 7 a UML for Dijkstra s
71. the algorithm had concluded that the shortest path from a to b was direct But when looking at c s neighbor b shorter path going through c exits between a and b i e d b 4 gt d c c b 2 1 3 d b is updated to 3 and z b updated to c b is added again to Q The next adjacent vertex is d which haven t covered yet d d is set to 7 and z d to c 48 The unsettled vertex with the shortest distance is extracted from the queue it is now b It is added to the settled set and its neighbors c and d are relaxed Figure 4 5 Third Iteration c is skipped because it has already been settled But a shorter path is found for d d d 7 gt d b b d 3 1 4 Therefore d d is updated to 4 and z d to b Then d is added to the Q set At this point the only vertex left in the unsettled set is d and all its neighbors are settled The algorithm ends The final results are displayed in red below in figure 3 6 m the shortest path in predecessor fashion d the shortest distance from the source for each vertex Figure 4 6 Fourth Iteration 49 4 4 UML for Dijkstra s shortest path algorithm Figure 4 7 a and 4 7 b corresponds the UML class diagrm for dijkstra s shortest path algorithm UML class diagrams are used to describe the static view of an application Rumbaugh et al 1999 the main constituents are classes and their relationships A class is a description of a concept and may have attributes and
72. type type FEATURE_COUNT number Eo Number of features about which to return information default 1 l pixel_column eel i coordinate in pixels of feature in Map CS EXCEPTIONS exception_format The format in which exceptions are to be reported by the WMS default XML Table 2 3 The parameters of a GetFeatureInfo request OGCWMS1 3 p39 2 9 3 2 WES The OGC Web Map Service allows a client to overlay map images for display served from multiple Web Map Services on the whereas the OGC Web Feature Service allows a client to retrieve and update geospatial data encoded in Geography Markup Language GML across the Web using platform independent calls OGC 1 1 0 p12 The WES standard defines interfaces and operations for data access and manipulation on a set of geographic features including OGC 1 1 0 p7 Get or Query features based on spatial and non spatial constraints Create a new feature instance Get a description of the properties of features Delete a feature instance WFS T Update a feature instance WFS T Lock a feature instance WFS T 28 By default the specified feature encoding for input and output is the Geography Markup Language GML which in turn is written in XML A WES specification provides 3 basic interfaces that allow it to service the requests that it receives from clients These are GetCapabilities DescribeFeatureType and GetFeature These are considered as a READ ONLY web feature servi
73. urce world was almost zero By working withopen source software on this project I learned how the open source projects are typically run and how one can make a contribution 7 4 Benefits of undertaking this project This project has been personally very beneficial from the point of view of acquiring in depth knowledge into integrating a system that includes an Postgis database a GIS server and front end technology to display geographic data Each of these had to be researched so in addition of gaining hands on experience with the chosen software information was also learned about other similar applications and the functionality they offer The underlying services of PostGis combined with GeoServer can be used for deploying any geographic data and allow the use of this information in many ways 1 e using OpenJump to access either the database directly or through GeoServer to process the data It makes viewing this geographic data very easy over the web using a product such as OpenLayers 7 5 Future research could be done The software developed in this work performs to show routes between one building to another building in OpenJump using dijkstra shortest path algorithm and can display the 86 layers in openlayer format and javascript was written two pick up the two points as a layer The following features could be added e Create table dynamically after picking the two points and display features as a layer e Create the routes fr
74. ute function bob O 10 ow Ww 000 YN N N NH N NN HH NN Ny P w N He ww U N ps JO Bb WN O WwW 00 N wm a ww U N ps Oo J O 10 00 CREATE OR REPLACE FUNCTION find route source building gid int target building gid int OUT INTEGER OUT INTEGER OUT FLOAT RETURNS SETOF record AS DECLARE s int find nearest_road source building gid f int find nearest_road target building gid EJBEGIN EFJRETURN QUERY SELECT FROM shortest_path E SELECT gid as id oO E H a m H 3 ct m ct fu te Q m ct H 3 ct m Q m be pa m 3 Q ct y Q E o pa m e te m 2 Lo pas O fu Lo 1 S Lo ct FROM dublin highwayi s f false false end of the block END LANGUAGE plpgsql Listing 6 4 find_route function In line 1 and 2 CREATE FUNCTION call creates the PL pgSQL function in the PostgreSQL database This CREATE FUNCTION command names the new function find route states its argument source building gid and target building gid as integers types OUT parameter allows to return outputs from a function without having to declare 71 a PostgreSQL type as output of the function The function s main code block then starts with a declaration section Line 4 defines return type which is set of record RETURNS SETOF record returns the multiple rows Line 9 and 10 declares the variable as int and another PL pgSQL
75. val String void getiD Integer compareTo arg0 GraphNode int getDistanced Integer selDistance distance Integer void Figure 4 7 b UML for Dijkstra s shortest path algorithm Lecture 6 2011 4 5 Function The Dijkstra shortest path algorithm is implemented as shown in Listing 3 1 The shortest path function has the following declaration pgRouting 2011 CREATE OR REPLACE FUNCTION shortest path sgl text source id integer target id integer directed boolean has reverse cost boolean RETURNS SETOF path result Listing 4 1 Shortest path function declaration 4 6 Arguments Input A sql query should return the set of the column with the following columns pgRouting 2011 SQL SELECT gid source target length FROM dublin_highwayl 51 estdb SELECT gid source target length FROM dublin_highway1 5 gid i source target i length aH boo tH 1 i 1 i 2 i 8065 43884257229 7i 13 i 14 i 399 760888836039 8 i 15 i 16 i 122 317192867977 9 i 17 i 18 14 1615912173981 16 i 19 i 26 66 4677521213594 11 i 21 i 22 i 16 5825862115612 12 i 23 1 24 i 186 825036781141 13 i 25 i 26 368 782965611611 14 i 27 i 28 29 5661372136707 15 i 29 i 28 i 138 413531476338 16 i 38 i 3i i 475 41876238508 127 321 33 56 3397053724588 Listing 4 2 Verfying all of the arguments from shortest_path function are displayed as a result of query from road data dublin_highway1 e id an int identifier of the edge
76. was used for the road data required for this project so it was necessary to understand about OpenStreetmap data OpenStreetMap is a free editable map of the world OSM Its aim is to create a set of map data that s free to use editable and licensed under new copyright schemes Haklay amp Weber 2008 First this started with mapping streets now it has already gone far beyond which include footpaths buildings waterways pipelines woodland beaches postboxes and even individual trees The project also includes administrative boundaries details of land use bus routes and other abstract ideas that aren t visible from the landscape itself 17 2 7 1 Data Format OpenStreetMap uses three basic primitive data models nodes ways and relations In mathematical terms openstreetmap data model is mixed graphs which consits of vertices and edges Bennett 2010 The default format for representing the data model is XML There are several attributes common to every primitive type Each has a numerical ID but these are only unique within each type so there could be a node way and relation all with the same ID number Bennett 2010 2 7 1 1 Nodes Nodes represents points in space which provides position information and all other primitives rely on nodes for their location In the figure the The Blue Blazer is represented as a node which is a pub in Edinburg Bennett 2010 amp o E des NS o Dy w E 5 Mm gt lt P z gt
77. which have both spatial used for shape file and non spatial attributes suitable to use when manipulating row data Spatial attributes are geometry valued and simple features are based on 2D geometry with linear interpolation between vertices OGCSFS1 1 20 Feature specifications schema was appropriate for used in order to return the list of feature tables from a database the list of geometry columns for any feature table in the database and the spatial reference system for any geometry column in the database The following basic functions were used to manipulate geometry object SRID Integer used to manipulate the Spatial Reference System ID of the geometric object AsBinary Binary allow well known binary representation of Geometry to their boundaries AsText String allow well known text representation of Geometry The following methods were used for testing Spatial Relations between geometric objects and to support spatial analysis respectively Contains anotherGeometry Geometry Integer Returns True if this Geometry spatially contains another Geometry Buffer distance Double Geometry Returns a geometry that represents all pointswhose distance from this Geometry is less than or equal to distance Calculations are based in the Spatial Reference System of the Geometry The following diagram illustrates the representation of geographic object and how they are connected on the space representing as point
78. with the software and it integrates easily with other software used in the project It was the ideal to for dataset storage as is a free and open source application and it easy to install and use PostgreSQL is a database server product when request are made to the database the server processes the request prepares the data and returns result to the application Mitchell 2005 Listing below shows the database service is running erver localhost localhost atabase postgres postgres ort 5432 5432 sername postgres postgres assword for user postgres pagi 8 4 2 gt ARNING Console code page 437 gt differs from Windows code page 1252 gt 8 bit characters might not work correctly See psql reference page Notes for Windows users for details Type help for help postgres 32 Listing 3 1 Verifying PostgreSQL database is working properly 3 2 1 1 Standard Compliance PostgreSQL includes most SQL which strongly conforms to ANSI SQL 2008 standard and has full support for subqueries including subselects in the FROM clause read committed and serializable transaction isolation levels PostgreSQL 1996 2010 3 2 1 2 Features PostgreSQL runs on all major platforms Its data integrity feature provides support for foreign keys joins views triggers and stored procedures in multiple languages It includes most SQL 2008 data types it also supports storage of binary large objects It supports co
79. xample According to Wladura 2007 the following data structures are used for this algorithm d stores the best estimate of the shortest distance from the source to each vertex m stores the predecessor of each vertex on the shortest path from the source S the set of settled vertices the vertices whose shortest distances from the source have been found Q the set of unsettled vertices Figure 4 2 shows the graph of Dijkstra shortest path algorithm starting at the source vertex a 4 1 AS a 3 2 d Figure 4 2 Initialisation in Dijkstra shortest path algorithm with source vertex a First iteration is done by adding source vertex a to the set O O isn t empty its minimum is extracted a again Then a is added to S and its neighbour is relaxed 47 Figure 4 3 First Iteration Vertices adjacent to a are b and c in green in figure 3 3 At first the best distance estimate from a to b is computed d b was initialized to infinity therefore the calculation will be d b d a a b 0 4 4 m b is set to a and b is added to O Similarily for c d c is assigned to 2 and z c to a Now O contains b and c As seen in figure 3 3 c is the vertex with the current shortest distance of 2 It is extracted from the queue and added to S the set of settled nodes Then the neighbours of the c a b and d are relaxed Figure 4 4 Second Iteration a is ignored because it is found in the settled set The first pass of
80. xes dublin_highwvayi_pkey PRIMARY KEY btree Cgid gt geom_idx gist the_geom gt source_idx btree source gt target_idx btree target gt heck constraints enforce_dims_the_geom CHECK lt st_ndimstthe_geom gt 2 enforce_geotype_the_geom CHECK Cgeometrytype lt the_geom gt MULTILINESTRING itext OR the_geom IS NULL gt enforce_srid_the_geom CHECK lt st_srid lt the_geom gt 29988 Listing 5 4 Verfying table dublin_highway1 was successfully altered adding source target and length column After this step assign_vertex_id function was ran to create network topology in dublin highwayl table containing road data Listing 5 5 shows that the assign_vertex_id was successfully run to create network topology connectivity information Restdb select assign vertex id dublin_highwayl cast 1 5 as float the ge om gid NOTICE CREATE TABLE will create implicit sequence zial column vertices Empr id CONTEXT SQL statement CREATE TABLE vertices tmp id serial PL pgSQL function assign vertex id line 14 at EXECUTE statement oK 1 row 59 Listing 5 5 Verfying the network topology was successfully created in psql For dublin_highway1 table After these steps testdb database looks like this public vertices_tmp i table public i vertices_tmp_id_seq Sequence postgres postgres Listing 5 6 Verifying the network topology was successfully created The f

Route Finding Using Geographic Information System

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