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GIS is Dead!!Long Live GIS!!!� Evolution of Standards for Geospatial data

has transformed Geographic Information System (GIS) to Geospatial Information Services (GIS)� Geography is becoming a part of everything� Location is becoming as ubiquitous as time

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What is a Web Service?� A web service is an application service that provides one or more functions that can be remotely requested � Each function within the service performs a specific task (e.g., generate a map)� Clients remotely invoke a function on a web server� Input parameters and data output are passed back and forth in XML format� Independent of programming language and operating system

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Web Service OperationWeb Server

(Listening for requests)1. Creates XML Request

2. Request sent to web service

3. Receives request and parses XML

4. Calls the function

5. Creates response XML with results

6. Response sent to client7. Receives response and parses

Client

Zone: 18Easting: 623,456.3Northing: 4,745,342.3

Convert UTM To Lat/Long

Processing….Longitude: -73.3456Latitude: 42.2753

Types of Geospatial Web Services� Map/Data Oriented ServicesMap Services (Image) Feature Services (Vector)Coverage Services (Grid)� Task Oriented ServicesGeocoding ServicesRouting ServicesGeoprocessing Services

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Access to spatial data using Web Services

Map Service OperationWeb Server/Map Server

Client

5. Map Server generates map as image file

1. Creates XML Request

2. Request sent to web service

3. Receives request and parses XML

4. Calls the map server to request map

6. Creates response XML with image file

7. Response sent to client8. Receives response, parses to extract image

and updates map

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WMS Connection using Google Maps

Google Basic Map in the Northern Philippines Satellite Map + WMS Layer

• Google Maps API significantly reduces the efforts to develop web map application and create mash-up application utilizing other source.

• Detailed and much information is not available and also takes long time to cover for minor or local places, such as Region II area.

WMS Connection using Virtual Globe Viewer

NASA WorldWind

Nowadays, Virtual Globe Viewers are used in several purposes such as education for geography, virtual tour, research, etc.

Google Earth

Dapple

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JVNMobileGISSkylab Spot Viewer & WMS Client

using Java J2ME emulator

WMS Connection using Mobile �� !"�#�� !"�#�� !"�#�� !"�#• Normally in GPS or Mobile GIS application, very simple map is initially

installed and made available for use. $WMS function enables to access more detailed map or overlay different

kinds of category map.

WMS - getCapabilties allows the server to advertise what it can do:� available layers� supported output projections� supported output formats� scale hints� extent of data XML format http://wgrass.media.osaka-cu.ac.jp/cgi-bin/gmapwms?request=Getcapabilities&version=1.1.0&service=WMS

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WMS - getMap allows the retrieval of a map from a web server user supplies bounding box, image size, format, error handling, etc… server responds with an “ image” , typically a web-ready format like GIF, PNG or TIFF http://wgrass.media.osaka-cu.ac.jp/cgi-bin/gmapwms?&SERVICE=WMS&VERSION=1.1.1&REQUEST=getMap&LAYERS=prov_bound&STYLES=&SRS=EPSG:4326&WIDTH=600&HEIGHT=500&FORMAT=image/png&BBox=-173.637,-11.9603,35.8775,83.8009

WMS – getFeatureInfo� allows the retrieval of simple feature attributes� user supplies an x,y coordinate pair and a layer of interest� server responds with attribute information in HTML, GML or arbitrary ASCII format

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Web Features Services (WFS)Basic WFS ServiceEvery WFS service MUST support the following functions:% GetCapabilities – Describes the capabilities and available layers % GetFeature – Gets and returns the geometry and attributes for all

features within a specified bounding box% DescribeFeatureType – Returns a description of a layer (feature type, field definitions, etc.)

Transactional WFS ServiceThe following functions are optional for providing editing within WFS

services:& Transaction – Allows specified features to be modified as an editing transaction (allows insert, update and deleting of features)& LockFeature – Creates a lock on the specified features (for locking during an editing transaction)

Feature Service OperationWeb Server/Map Server

Client

5. Map Server selects features and attributes from database and generates GML

1. Creates XML Request

2. Request sent to web service

3. Receives request and parses XML

4. Calls the function to request features

6. Creates response with GML embedded

7. Response sent to client8. Receives response and

parses to extract GML

9. Renders features on map display

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WFS - getCapabilities' allows the server to advertise what it can do:( available layers or types( supported output projections( supported output formats( extent of data' XML format

WFS - getFeature( allows spatial queries, attribute queries or both against a layer( response is typically a GML instance document that conforms to the describeFeatureTyperesponse of the server( queries conform to the GML filter encoding standard( equates logically to the various MapServer query modes

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WFS - describeFeatureType' returns detailed information about a layer or group of layers' format is an XML Schema

Transactional WFS( WFS-T, what WFS was really created for( additional modes to lock features (getFeatureWithLock & lockFeature)( supports INSERT, UPDATE and DELETE operations via transaction request( relatively few commercial or open source solutions (Geoserver is one of them)

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Registered Data Through WFS-T

WFS Connection using Desktop GIS

uDig Desktop GIS Client

• Example for WFS -T and WFS using uDig Desktop GIS.

WCS (Web Coverage Service)

A WCS connection is composed of 3 operations. WCS client retrieves un-rendered geospatial coverage (raster data) from WCS server. Coverage data includes values or properties of regularlyspaced locations, and is returns as Geotiff, HDF, CDF, GTOPO30or other grid data format according to client’s requests.

1.GetCapabilities : returns an XML document with metadata of the information available on a WCS Server.

2.GetCoverage : returns values or properties of regularly spaced locations, bundled in a requested format.

3.DescribeCoverage : provides the information for a client to assess the data's fitness for use, and to formulate deitailed GetCoverage requests.

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WCS Connection using Desktop GIS

gvSIG Desktop GIS Client

Task Oriented ServicesGeocoding Services& Client passes in one or more addresses to a web service which

geocodes the data and returns one or more x,y coordinates

Routing Services& Client passes in one or more locations to a web service which computes the optimal route and returns the route and optional text based directions

Geoprocessing Services& Any type of geoprocessing/spatial analysis can be done via a web service (buffer, clip, multi-step model, etc.)& Input and output varies based on the geoprocessing performed & Client passes input parameters to a web service which performs the geoprocessing and returns the results

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Web Processing Service( Recently, Open Geospatial Consortium (OGC) launches a draft specification of Web Processing Service (WPS) , originally named Geoprocessing Service.( The specified Web Processing Service provides client access to pre-programmed calculations and/or computation models that operate on spatially referenced data.6 The result of request process are available to

download for further analysis at user’s machine.

PyWPS(Python Web Processing Service)( The main advantage of PyWPS is, that it has

been written with native support for GRASS.6 Access GRASS modules via web inteface should be as easy as possible.( PyWPS is written in Python programming

language.( Current version is 2.0.0( http://pywps.wald.intevation.org/index.psp

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WPS Interface( GetCapabilities – This operation allows a client to describe the abilities of specific server implementation.( DescribeProcess – This operation allows a client to request detailed information about one or more process that can be executed, including the necessary input parameters and formats, and the outputs.( Execute – This operation allows a client to run a specified process implemented by the WPS, using provided input parameter values and returning the output produced.

PyW

PS

System

WFS WCS GeoTiff, GML

PostgreSQL/PostGIS

Shp

GeoTiff

GML

Web Processing Service Server

User

Execute Request

GML or GeoTiff Result

GRASS GIS

Web-Mapping Application

User

Execute Request

GML or GeoTiff Result

Desktop Internet GIS

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WPS : GetCapabilities Interface' ppt¥getcap01.jpg

http://mizu.info.gscc.osaka-cu.ac.jp/cgi-bin/wps.py?service=wps&version=0.4.0&request=getcapabilities

WPS : DescribeProcess Interface

http://mizu.info.gscc.osaka-cu.ac.jp/cgi-bin/wps.py?service=wps&version=0.4.0&request=describeprocess&Identifier=shortestpath

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WPS : Execute Interface[ProcessAccepted]

http://mizu.info.gscc.osaka-cu.ac.jp/cgi-bin/wps.py?service=wps&version=0.4.0&request=execute&Identifier=shortestpath&Datainputs=cost,0,x1,596527,y1,4921298,x2,598173,y2,4923383&store=true&status=true

WPS : Execute Interface[ProcessStarted]

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WPS : Execute Interface[ProcessSucceeded]

**Execute Requesthttp://wps.org/cgibin/wps.py?service=wps&

version=0.4.0&request=execute&

Identifier=shortestpath&Datainputs=cost,0,x1,596527,y1,4921298,x2,598173,y2,4923383&store=true&status=true

PyW

PS

System

WFS WCS GeoTiff, GML

PostgreSQL/PostGIS

Shp

GeoTiff

GML

Web Processing Service Server

User

Execute Request

GML or GeoTiff Result

GRASS GIS

Web-Mapping Application

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WPS : Result[GML]

Demo site

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PyW

PS

System

WFS WCS GeoTiff, GML

PostgreSQL/PostGIS

Shp

GeoTiff

GML

Web Processing Service Server

User

Execute Request

GML or GeoTiff Result

GRASS GIS

Web-Mapping Application

Real-Time Data

WPS and SOS integration6 Due to the capability of WPS that allows to access distributed geospatial data across the network (such as WCS and WFS). 6 It is possible to utilize the observation from SOS

server.6 The result from SOS is encoded in XML flowing the OGC’s Observations & Measurements (O&M) schema.6 Presently, WPS are not able to directly use this observation data in further processing. 6 The observation is converted to a feature object as

GML document, which is an acceptable data format for WPS.

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SOS Result

SOS Result -> GML

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Demo site : SST

http://mizu.info.gscc.osaka-cu.ac.jp/waterwqi/

Demo site : Turbidity Index

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