Transcript WPS&SOS

Development of Geoprocessing Service
with Realtime Data Using WPS and SOS
Open Standard
Sarawut Ninsawat, Venkatesh Raghavan
Graduate School for Creative Cities
Osaka City University
FOSS4G2007 24-27 September 2007
Introduction
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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).
FOSS4G2007 24-27 September 2007
Dynamic Web-GIS
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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.
FOSS4G2007 24-27 September 2007
Web Processing Service
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Recently, Open Geospatial Consortium (OGC)
launches a draft specification of Web Processing
Service (WPS) , originally named
Geoprocessing Service.
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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.
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PyWPS
(Python Web Processing Service)
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PyWPS is written in Python programming
language.
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PyWPS implement OGC’s Web Processing
Service standard
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GRASS Go Web
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.
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WPS Interface
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GetCapabilities – This operation allows a client to
describe the abilities of specific server implementation.
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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.
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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.
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WPS : GetCapabilities Interface
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ppt\getcap01.jpg
http://mizu.info.gscc.osaka-cu.ac.jp/cgiFOSS4G2007 24-27 September 2007
bin/wps.py?service=wps&version=0.4.0&request=getcapabilities
WPS : DescribeProcess Interface
http://mizu.info.gscc.osaka-cu.ac.jp/cgibin/wps.py?service=wps&version=0.4.0&request=describeprocess&Identifier
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=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,y
2,4923383&store=true&status=true
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WPS : Execute Interface
[ProcessStarted]
http://mizu.info.gscc.osaka-cu.ac.jp/wpsoutputs/executereponse-2007-6-18-15FOSS4G2007 24-27 September 2007
9-3.xml
WPS : Execute Interface
[ProcessSucceeded]
http://mizu.info.gscc.osaka-cu.ac.jp/wpsoutputs/executereponse-2007-6-18-15FOSS4G2007 24-27 September 2007
9-3.xml
Web Processing Service Server
GML
GRASS GIS
PyWPS System
GeoTiff
Shp
Execute Request
GML
or GeoTiff Result
User
Web-Mapping
Application
PostgreSQL/PostGIS
**Execute Request
http://wps.org/cgibin/wps.py?service=wps&
version=0.4.0&request=execute&
Identifier=shortestpath&Datainputs=cost,0,x1,596527,y1,4921
298,x2,598173,y2,4923383&store=true&status=true
WFS
WCS
GeoTiff,
GML
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24-27 September 2007
WPS : Result
[GML]
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Demo site
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Web Processing Service Server
GML
GRASS GIS
Execute Request
PyWPS System
GeoTiff
Shp
GML
or GeoTiff Result
Web-Mapping
Application
PostgreSQL/PostGIS
WFS
WCS
GeoTiff, GML
Real-Time Data
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User
Sensor Network
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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.
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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.
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Wireless Sensor system
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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.
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Sensor Web Enablement
(SWE)
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Sensor Web Enablement
(SWE)
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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.
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SPA [Sensor Planning Service]
SAS [Sensor Alert Service]
WNS [Web Notification Service]
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Sensor Observation Service
(SOS)
GetObservation
Observations/Measurements
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SOS Result
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Implementation of Real-time
unmanned modeling map
Sensor Observation
Service
(SOS)
WFS
WCS
Web Processing Service
(WPS)
Real-time map
Update in situ data to modeling
computation
Water Quality demonstrate is
Web-Mapping
developing.
Application
In this demonstrate, simulated sensor
nodes are used to supply a water quality
value to SOS.
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GeoTiff, GML
User
WPS and SOS integration
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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.
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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.
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SOS Result -> GML
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Water Quality Index (WQI)
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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.
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The results can also be used to determine if a
particular stretch of water is considered to be
"healthy."
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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)
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WQI Calculation
n
WQI  Antilog[
 W log
n
n 1
10
q n]
qn that is a quality rating is computed using the following equation.
qn 100V actual  V ideal  V standard  V ideal 
Where
Vactual : actual amount of n parameter from analysis
Videal : 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.
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WQI Calculation
Where W (Weight factor) is computed using the following
equation.
Wn 
K
Sn
Where K is proportionality constant that is derived from
1
K
n
(
 1S )
n 1
i
Where Sn and Si are the WHO standard values of each water quality
parameters.
FOSS4G2007 24-27 September 2007
WQI
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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.
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Demo System : WQI
(Biwa Lake Supplies water to Osaka)
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http://mizu.info.gscc.osaka-cu.ac.jp/waterwqi/
Demo system :
SST (WCS data source)
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http://mizu.info.gscc.osaka-cu.ac.jp/waterwqi/
Demo site :
Turbidity Index (WCS data source)
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Conclusion
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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.
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Thank you
FOSS4G2007 24-27 September 2007