free and open source web mapping
TRANSCRIPT
Free and Open Source Web Mapping
Prof. Maria Antonia Brovelli, Dr. Eng. Giorgio ZamboniPolitecnico di Milano – Como Campus – Italy
2Geospatial Web
Users
Catalogues
Data
Processes
INTERNET
3Web MappingWeb Map and Geodata
Servers Web Map and Geodata Clients
INTERNET
4Map mashing-upServers
Clients
INTERNET
5Interoperability / Standardization
• Open and interoperable components
• Interchangeable data
• De jure standard: technical instruction set by national and/or international standardization organizations (ISO/OGC/National standards)
• De facto standard: technical instruction used by a noteworthy number of people and/or organizations.
6OGC Web Service (OWS)
• XML (eXtensible Markup Language) is used for the definition and the description of applications. The communication is based (in the majority of cases) on the HTTP protocol. Because of using XML, Web Services are platform and OS-independent.
• The functioning of OWS (OGC Web Services) can be described in four steps:• the client contacts the server and queries it about its
functionalities• the server sends back to the client an XML document
containing the functionalities of the supported service• the client asks the server for data• the server provides the data as requested
7WMS Example
Client Server
getCapabilities
XML Service Metadata
getMap
Map
Map AMap BMap C
…
Map AMap BMap C
…
AB
C
Map B
8OGC Web Map and Geodata Services
• Data Delivery:• WMS: service that generates maps and
makes them available as images or as a series of graphical elements
• WFS: service that generates geographic entities or features. If the service is “transaction” (WFS-T), data manipulation is allowed
• WCS: service that generates geospatial coverages, that are geospatial information representing space-varying phenomena (fields)
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• Data formats:• SFS: Simple Feature Standard• GML: Geography Markup Language • KML: Keyhole Markup Language
• Data search:• CSW: Catalogue Service• WFS-G: Gazetteer Service
• Other:• WPS: Web Processing Service • CTS: Coordinate Transformation Service• WTS: Web Terrain Service • SLD: Styled Layer Descriptor • WMC: Web Map Context
OGC Web Map and Geodata Services
10FOSS Web Map - Geodata Servers (1)
Platform independent
Windows, Linux, Mac-OSX
Operating System:
JavaCLanguage:
WMS, WFS(-T), WCS, GML, KML, SLD
WMS, WFS(-T), WCS, GML, SLD, WMC
OGC:www.geoserver.orgwww.mapserver.orgWeb:GPLMITLicense:2001mid ‘90Birth:
11FOSS Web Map - Geodata Servers (2)
Platform independent
Windows, LinuxOperating System:
JavaC++Language:
WMS, WFS(-T), WCS, GML, CSW, WFS-G, WPS, WTS, SLD, WMC
WMS, WFSOGC:wiki.deegree.orgwww.mapguide.osgeo.orgWeb:LGPLLGPLLicense:20052004Birth:
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• They are interactive viewers in the most of cases simply running in a web browser (Mozilla Firefox, Opera, Internet Explorer, etc.). Sometimes, depending on the technology adopted, plug-ins, i.e. pieces of software providing specific functionalities not available in the simple browser interaction, are requested.
• New generation web map and geodata clients are completely independent from the server application that lies behind them: they communicate indifferently by means of OGC open protocols with MapServer, GeoServer, MapGuide, deegree, etc.
• By means of this kind of applications, which renders maps from Web Map and Geodata Services, users can navigate maps, zoom in, zoom out, pan, click and query, turn layers on and off or add more maps. They can additionally edit map features (if data are served by a Transactional Web Feature Service), build their own maps, contacting different services on different machines and save them to be used at any time or to be shared.
Web Map and Geodata Clients (1)
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An example
Different languagesScalebar
Reference map
Legenda
Main map
Scale
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Zoom full extent
An example
BackZoom in/out
ForwardZoom to SelectedZoom inZoom outPan
IdentifySelectToolTipMeasureAdd Point of
InterestRefresh Map
1515
An example
WMS ServicesWFS ServicesData stored in the local server (e.g.: shapefiles, rasters, MapInfo tables and all the other formats supported by MapServer)
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An example
Searching tools:
Searchitem
Identify
Select
Tool Tip
:
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Web mapping client
comparison(German Carrillo, 2010)
Web Map and Geodata Clients (2)
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• Previous products are nicely presented for comparison in “Web mapping client comparison v.4” by German Carrillo (may 2010) (*)
• The comparison is divided in three parts:• general description: license, origin country, origin
company or entity, documentation (languages, formats, level [users, developers]), OSGeo support, comments;
• technical features: source code language, API language, OGC services supported, support of tile-based maps, need of proprietary plug-ins, inclusion of metadata component, mailing lists;
• links of interest: screenshot, current version, official website, documentation, features/roadmap, gallery/demo.
(*) http://geotux.tuxfamily.org/index.php?option=com_myblog&task=view&id=257&Itemid=59&lang=en
Web Map and Geodata Clients (3)
19Desktop Map and Geodata Clients (1)
Windows, Linux, Mac-OSX
Windows, Linux, Mac-OSX
Operating System:
CCLanguage:
WMS, WFS(-T), SFS, GML, KML
WMS, WFS, GML, WPS
OGC:www.qgis.orggrass.osgeo.orgWeb:GPLGPLLicense:20021982Birth:
Quantum GISGRASS
20Desktop Map and Geodata Clients (2)
Platform independent
Platform independent
Operating System:
JavaJavaLanguage:
WMS, WFS(-T), SFS, GML, WPS, SLD
WMS, WFS(-G), WCS, GML, KML, CSW, SLD
OGC:www.openjump.orgwww.gvsig.orgWeb:GPLGPLLicense:20022003Birth:
OpenJumpgvSIG
21Desktop Map and Geodata Clients (3)
Platform independent
MS Windows Operating System:
JavaC#, C++, Visual Basic, .NET
Language:
WMS, WFS(-T), SFS, GML, WPS, SLD
WMS, WFSOGC:udig.refractions.netwww.mapwindow.orgWeb:LGPLMozillaLicense:20042004Birth:
uDigMapWindow
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• Currently the most of the Internet viewers are bi-dimensional (horizontal).
• Virtual globe: a 3D representation of the EarthAdvantages:• more immersive effects • intuitive interactions• ability to freely move around in the virtual
environment by changing the viewing angle and location
• capability of representing many different views on the surface of the Earth
Multi-D Map and Geodata Clients (1)
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Comparison of Open Source Virtual Globes presented at FOSS4G-2010 Barcelona by Mathias Walker, Pirmin Kalberer(http://2010.foss4g.org/presentations/3690.pdf)
OssimPlanetOssimPlanet
NASA World Wind Java SDKNASA World
Wind Java SDK
gvSIG 3DgvSIG 3DosgEarthosgEarth Norkart VirtualGlobe
Norkart VirtualGlobe
Earth3DEarth3D
MarbleMarble QGIS 3DQGIS 3D
deegree 3Ddeegree 3D
Multi-D Map and Geodata Clients (2)
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• SDK (Software Development Kit)• Virtual Globe • NASA Open Source Agreement License• Multi-Platform (Java: “Write Once, Run AnyWhere”)• JOGL (Java OpenGL 3D - Engine)• Client – WMS Server (v0.6 nightly builds) • Web: worldwind.arc.nasa.gov/java
NASA World Wind (Java SDK)
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Main interfaces:• Globe: represents the planet's shape and
terrain (ellipsoid and terrain)• Layer: overlaps geospatial information to the
Globe (images, icons, markers, 3D objects, …)• Model: combines the Globe and Layers• SceneController: controls the rendering of the
Model• View: controls the user's view of the Model
(location – camera settings, …)
WWJ SDK Architecture (1)
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WorldWindow
Model
Configuration (Global)
Globe
Tessellator
Notifier (Global)
Frame ControllerView
Layer
Cache
Web
Scene Controller
Application
Canvas
Window Environment (Swing, AWT, etc.)
WWJ SDK Architecture (2)
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• Servers NASA – USGS (U.S. Geological Survey):
• DTM:• SRTM30Plus (30 arc-sec ~900m), SRTM3
v2 v4.1 (3 arc-sec, ~90m), ASTER (~30m), USGS NED (~30m, ~10m US only)
• IMAGERY:• BlueMarble (BMNG 1Km), i3-Landsat (15m),
USGS Ortho-Topo (1m US only), Urban Area Ortho (0.5 – 0.25m selected US city)
WWJ SDK Architecture (3)
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• Microsoft has allowed World Wind to incorporate Virtual Earth high resolution data for non-commercial use.
• It is possible to take from a whichever OGC compliant WMS server the geo-referenced images (and maps) we want to project on the globe.
• It is possible to take from specific WMSs, whose code is made available by NASA, the digital elevation models we want to superimpose to the geoid model implemented within the platform.
Construction of the scenario
WWJ SDK Architecture (4)
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time
WWJ-CLIENTRemote
Database
THEMATIC MAPS (2D)
RemoteDatabase
IMAGERY
RemoteDatabase
DTM
WMSSERVER(WWJ0.6)
WMS SERVER
WMS SERVER
2½D
Mapt=t0
Mapt=t1
Mapt=t2
• Projection on the Earth surface (2½D) of time varying thematic maps
3½D Model (1)
Scenario
WWJ SDK
3½D Model
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Original dataset – (Landsati7 + SRTM)Custom orthophotoCustom orthophoto + thematical mapCustom orthophoto + DTM + thematical mapCustom orthophoto + DTM + thematical map
3½D Model (2)
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Thematical map: t = t0Thematical map: t = t1Thematical map: t = t2Thematical map: t = t3Thematical map: t = t4
3½D Model (3)
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3D Thematical MapsSHP FILE
A
C
D
B
E DBAttributes
(mdb, xml, …)
Natural domain (lake)
SHP FILE
A
B
C
D
E
DBAttributes
(mdb, xml, …)
Artificial domain (building)
4D Model Irregular shapes (1)
WWJ-CLIENTSHPLoader
GeometryBuilder
334D Model Irregular shapes (2)
A(t0) A(t1) A(t3) A(tN)A(t2) A(…)
3D Thematical Maps
… t
A
t1 t2 t3 tNt0
Feature attributes
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time
WWJ-CLIENT
WMSSERVER
RemoteDatabase
IMAGERYWMS
SERVER
RemoteDatabase
3D MODEL(SHP)
ATTRIBUTES (DB)
RemoteDatabase
DTM
3DWEB SERVER
Attributet=t0
Attributet=t1
Attributet=t2
4D Model Irregular shapes (3)
Scenario
WWJ SDK
4D Model
354D Model Irregular shapes (4)
Olbia BuildingsMean Energy – Classification by ColorAttribute: Incentive – Thematized by ColorAttribute: Incentive – Thematized by Color and Height
36Doxel Model (1)
VOXEL (3D)v
WWJ-CLIENT
+time
(1D)
4D Thematic Map
NetCDFLoader
GeometryBuilder
NetCDF FILE
3D VARIABLES
DIMENSIONSATTRIBUTES
units
…
sourcesCOORDINATES
DOXEL (4D) (Dynamic voxel)
=v(t0)v(t1)v(t2)v(t3)
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time
WWJ-CLIENT
WMSSERVER
RemoteDatabase
IMAGERYWMS
SERVER
RemoteDatabase
3D MODEL+
ATTRIBUTES(NetCDF)
RemoteDatabase
DTM
3DWEB SERVER
Attributet=t0
Attributet=t1
Attributet=t2
Doxel Model (2)
Scenario
WWJ SDK
4D Model
38Doxel Model (3)
v(t)
0 1 2 3 … N
v(t0) v(t1) v(t3) v(tN)v(t2) nodata
… t
v
t1 t2 t3 tNt0
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LONGITUDE SECTION
GET ATTRIBUTE INFO
INFO
t
Attribute Value
Doxel Model (4)
HORIZONTAL SECTION
LATITUDE SECTION
• Interactions with the 3D model
40EST-WA (1)
(Environment Space and Time Web Analyzer)
•Metadata Viewer•2D Viewer•Data Filter
EST-WA2D 3D Geometry
Builder
Localcache
•4D Viewer(WWJ engine)
•2D Profile viewer
EST-WA3D
EST-WA
NetCDFdata
NetCDFdata
RemoteServer
http
DTMTexture
41EST-WA (2)
EST-WA3D
EST-WA2D: METADATA VIEWER EST-WA2D: DATA FILTER