foss4g2007 24-27 september 2007 development of geoprocessing service with realtime data using wps...

FOSS4G2007 24-27 September 2007

Development of Geoprocessing Service with Realtime Data Using WPS and SOS

Open Standard

Sarawut Ninsawat, Venkatesh RaghavanGraduate School for Creative CitiesOsaka City University

http://www.foss4g2007.org/


Introduction Rapid urbanization is global phenomenon and it is estimated that

60% of the worlds population will be urban by the year 2050. Providing a clean, safe and creative urban environment has become

a top priority for many nations. Clean and safe water is one of the precious resource for the urban

population . A comprehensive system that could monitor a water quality and

provide information for to stake-holders needs to be implemented Such a system should;

Provide access to geospatial water quality data over the Web for collaborating all the departments.

Allow spatial analysis and environmental modeling functionality for decision making.

Afford timely reporting of events through real-time in situ measurement (not a archive system).


Dynamic Web-GIS Many standards for a Spatial Data Infrastructure

(SDI), which aims to facilitate and standardize the storage and access of to spatial data

Availability of spatial analysis capability in Web-GIS applications would allow extraction of knowledge from spatial data repositories.

GRASSLinks (Huse, 1995) is one of the early implementation of analytical Web GIS for providing public access to environmental information.

Similarly, pgRouting provides some core tools for Location Based Services.

However, only the visualization and searching is inadequate for monitoring purposes.


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. The result of request process are available to download for

further analysis at user’s machine.


PyWPS (Python Web Processing Service)

PyWPS is written in Python programming language.

GRASS Go Web PyWPS implement OGC’s Web Processing

Service standard Operable with any other tool or just with Python itself

even without GRASS GIS in the background Current version is 2.0.0 http://pywps.wald.intevation.org/index.psp.


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.


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


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]

http://mizu.info.gscc.osaka-cu.ac.jp/wpsoutputs/executereponse-2007-6-18-15-9-3.xml


WPS : Execute Interface[ProcessSucceeded]

http://mizu.info.gscc.osaka-cu.ac.jp/wpsoutputs/executereponse-2007-6-18-15-9-3.xml


**Execute Request

http://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

Py

WP

S S

ys

tem

Py

WP

S S

ys

tem

WFSWFS WCSWCS GeoTiff, GMLGeoTiff, GML

PostgreSQL/PostGISPostgreSQL/PostGIS

ShpShp

GeoTiffGeoTiff

GMLGML

Web Processing Service Server Web Processing Service Server

UserUser

Execute Request

GML or GeoTiff Result

GRASS GISGRASS GIS

Web-Mapping Web-Mapping ApplicationApplication


WPS : Result[GML]


Demo site


Py

WP

S S

ys

tem

Py

WP

S S

ys

tem

WFSWFS WCSWCS GeoTiff, GMLGeoTiff, GML

PostgreSQL/PostGISPostgreSQL/PostGIS

ShpShp

GeoTiffGeoTiff

GMLGML

Web Processing Service Server Web Processing Service Server

UserUser

Execute Request

GML or GeoTiff Result

GRASS GISGRASS GIS


Real-Time DataReal-Time Data


Sensor Network In the past, to acquire an information

from remote place consume time and money.

Environmental monitoring requires real-time reporting and archiving of events and phenomenon.

Sensors and communications chips can be embedded in data logging devices enabling them to.

communicate with other devices, serviced and upgraded remotely through computer network.

collect huge amount of information at low costs via a network of field sensors.


Wireless Sensor system

The sensor-node “Field Server” equipped with a Web server and Wireless Lan was introduced for a remote field monitoring system Manage and periodically collect monitoring data via the

Internet connection from remote place. More than 40 Field Servers are currently deployed in

various parts of Japan, the United States, Thailand, China, Korean and Taiwan.

However, the lack of integration and communication between these sensor networks, often leaves such valuable information underutilized.


Sensor Web Enablement (SWE)


Sensor Web Enablement (SWE)

O&M [Observations & Measurements Schema] SensorML [Sensor Model Language ] TML [Transducer Markup Language] SOS [Sensor Observation Service]

In this study, 52N Sensor Observation Service (52NSOS) has been used.

Provides the framework of the sensing resources to service users. SPA [Sensor Planning Service] SAS [Sensor Alert Service] WNS [Web Notification Service]


GetObservation

Observations/Measurements

Sensor Observation ServiceSensor Observation Service(SOS)(SOS)


SOS Result



Sensor Observation Sensor Observation ServiceService(SOS)(SOS)

Web Processing ServiceWeb Processing Service(WPS)(WPS)

WFSWFS

WCSWCS

GeoTiff, GMLGeoTiff, GML

UserUser

Implementation of Real-time unmanned modeling map

Real-time mapUpdate in situ data to modeling computationWater Quality demonstrate is developing.In this demonstrate, simulated sensor nodes are used to supply a water quality value to SOS.


WPS and SOS integration Due to the capability of WPS that allows to

access distributed geospatial data across the network (such as WCS and WFS). It is possible to utilize the observation from

SOS server.

Presently, WPS are not able to directly use this observation data in further processing. The observation is converted to a feature

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


SOS Result -> GML


Water Quality Index (WQI) The WQI, which was developed in the early

1970s, Over 100 water quality experts were called upon to

create a standard Water Quality Index. Monitor water quality changes in a particular water

supply over time, Compare a water supply's quality with other water

supplies in the region or from around the world.

The results can also be used to determine if a particular stretch of water is considered to be "healthy."


Seven water quality parameters

Dissolved Oxygen (% Saturation) Nitrate (mg/L) pH Total Phosphate (mg/L) Total Dissolved Solids (mg/L) Temperature Change (C) Turbidity (NTU)


WQI Calculation

n

nnn q

110 ]logW[AntilogWQI

VVVVq idealstandardidealactualn 100

WhereVactual : actual amount of n parameter from analysisVideal : ideal value of water quality parameter Videal for pH = 7, D.O. = 14.6 mg/L and for other parameters is zero.Vstandard: recommended WHO standard value of water quality parameter.

qn that is a quality rating is computed using the following equation.


WQI Calculation

S

K

nn W

)1(

1

1

n

niS

K

Where W (Weight factor) is computed using the following equation.

Where K is proportionality constant that is derived from

Where Sn and Si are the WHO standard values of each water quality parameters.


WQI The Q-value for each test should then be multiplied by the

weighting factor. Summarize of all Q-value is a Water Quality Index rating. You may perform as many of the following tests as you

wish. However, at least 6 must be completed, Divide the total of

the Q-value by the total of the Weighting Factor to obtain the Water Quality Index rating.


Demo System : WQI (Biwa Lake Supplies water to Osaka)

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


Demo system : SST (WCS data source)

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


Demo site : Turbidity Index (WCS data source)


Conclusion

The integration of two OGC-compliant open standards to create a comprehensive geoprocessing service utilizing real-time data from sensor observation network has been described

SOS can be a valuable data source for WPS via the integrated client developed as a part of this study

Due to standardization, the usage of geodata as well access to real-time data much easier and less expensive allows better decision making.

We are now working on development of field water quality sensor that could be integrated with the present system for monitoring groundwater quality urban areas.


Thank you

foss4g2007 24-27 september 2007 development of geoprocessing service with realtime data using wps...

Documents

web pywps

getcapabilities slide

webgis applications

dynamic webgis

client access

spatial data repositories

wps interface getcapabilities

realtime data