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VOYAGER Data Explorer:Architecture and Technologies
See also the the Voyager Developer Website and early Applications
Layered Map
Time Chart
Providers Users
Vector
GIS Data
XDim DataSQL Tables
WebImages
Voyager Web Services
Publish, Find, Bind
Data & Tool Catalog
Uniform Access
Scatter Chart
S u p p o r tCoord./Cooperation T e c h n o l o g i e s
Select, Overlay, Explore; Multidimensional data
Maintain Distributed Data; Heterogeneous coding , access
Connect providers to users; Homogenize data access
Voyager Spatio-Temporal Data Explorer Built and Used by a Virtual Community
Layered Map
Time Chart
Providers Users
Vector
GIS Data
XDim Data
SQL Table
Web
Images
Voyager Web Services
Publish, Find, Bind
Data & Tool Catalog
Uniform Access/Retrieval Scatter Chart
The Dvoy Project
DVOY is a graphic browser for distributed, heterogeneous, multidimensional datasets
The initial Dvoy infrastructure was developed at CAPITA, with NSF support
Further services for data access, processing and viewing are expected from the community
The project evolution is to ride 'web services wave‘ of the Internet
CAPITA Support: – NSF ITR Workgroup Collab. Tool: Aug 2001 - Aug 2004
– EPA Web-based Visibility: Aug 2001 - Apr 2003
– NOAA ASOS Visibility: Aug 2001 - May 2002
– MARAMA Chemical Trajectory Tool: Aug 2002 - July 2003
– EPA OAQPS Global Transport Analysis: Nov 2002 – Oct 2003
In-kind support by organizations participating in DVOY-based data sharing
Dvoy Data Model
Multi-Dimensional Data Model
Data can be distributed
over 1,2, …n dimensions
1 Dimensional e.g. Time dimension
ij
k
ji
Data Granule
i
1 Dimensional
e.g. Location & Time
1 Dimensional e.g. Location, Time &
Parameter
View 1
Data Space
View 2
Views are orthogonal
slices through data space
4 D Geo-Environmental Data Cube (X, Y, Z, T)
Environmental data represent measurements in the physical world which has space (X, Y, Z) and time (T) as its dimensions.
The inherent dimensions for geo-environmental data are: Longitude X, Latitude Y, Elevation Z and Time T.
Semi-Static Views (slices) through 4D Data Space
• Possible Cross-sections through the 4 D Data space
- data point..Temperature (xi, yi, zi, ti)
- image Temperature (xrange , yrange, zrange, trange)
XY MAP: Z,T fixed
Vertical Profile:XYT fixed
Time Chart: X,Y,Z fixed
Vertical Cross sect: YT fixed Vertical Cross sect: XT fixed
Vertical Profile Trend:
X,Y fixed
Web Services
Web Services Components and Actions
• Service providers publish services to a service broker.
• Service users find the needed service and get access key from a service broker• With the access key, users bind to the service provider• The result is a dynamic binding mechanism between the service users and providers
Service Broker
Service Provider
PublishFind
BindServiceUser
Components: Provider – User – Broker
Actions: Publish – Find - Bind
Interoperability through a Layered Protocol Stack
• Web Services are implemented on a layered stack of technologies and standards
• The lower layers enable binding and exchange of messages; higher levels enable interoperability
• Applications are formed dynamically from distributed components through publish-find-bind mechanisms
TCP/IP, HTTP, FTP
ASCII, XML, etc.
HTML, XML OGC -GML
OGC Coverage, CoordTransfom, WMS
HTTP, SOAP
WSDL
UDDI OGC Catalog
WSFL, XLANG
StandardsInteroperability
Comm. Protocols
Data Encoding
Data Schema
Data Binding
Web Service
Service Integr.
Service Discovery
Service Descript.
Connectivity
Web PublishHTTP, FTP
Data Access though a Web Service Adapter
Service Cataloger
Service Consumer
Ordinary web content can be delivered as a Web Service through a Proxy Server.
• The Wrapper Service converts HTTP/FTP service to XML Web service
• The Wrapper Service is published as a web service to the Broker
• The User finds the service from the broker and accesses the Wrapper to use the service
Service Wrapper
HTTP/FTP
ServiceService
User Chain
FindUDDI, WSDL
PublishUDDI, WSDL
AccessSOAP, XML
Web Application: Chained Web Services
• A Web Service Provider may also be a User of other services • Multiple web services can be chained into an interactive workflow system • The result is an agile application that can be created ‘just in time’ by the user for a specific need
Service Broker
Service Provider/User
PublishFind
BindServiceUser
Chain
Service Provider
Bind
Chain
Features of the DVOY XML Web Service Architecture
Interoperability: Platform and language independence; based on Web Services (XML,SVG)
Legacy Support: Encapsulating existing data and exposing them as Web Services. (Access to standard HTTP/FTP servers)
Just-in-time integration: Discovery, access to and ad-hoc chaining of services.
(Future: Agile app building)
DVOY Web Services
DVOY draws on three basic web services:
DataCatalogWrapping service is for data registration, finding and wrapping information
DataAccess service provides uniform access to heterogeneous, distributed, multidim. data
DataPortrayal service prepares input data in form suitable for rendering
Applications….
• Voyager Data Browser
Data Catalog
• All the data in the system are to be distributed on the Web and maintained by their custodians
• The purpose of the catalog is to help finding and and accessing the data
• Catalog would be limited to data that can be accessed/merged in DVOY
Catalog of Multidimensional Datasets
• Designed to Publish, Find(Select), Bind(Access) and Render distributed datasets• Publishing is though an open web interface for user/broker registration of datasets• Finding a dataset is aided by a metadata on Provider and Dataset• Binding (data access) information is contained in the Dimensional Tables• Rendering parameters are also contained in the Dimensional Tables
Geo-referenced Map Image: Image IndexedVariable Time , Var GeoRect, Var Sensor
SatGeoImg
CapImgID Universal ID
ProviderURL URL
SourceURL URL
ImageURL URL
ProviderAbbrev NASA GSFC
ImageDescription Text
Sensor Enumerated
DateTime DateTime
LatMin -65
LatMax 65
LonMin - 180
LonMax 180
ImageWidth For size verification
ImageHeight
MarginLeft For trimming
MarginTop
MarginRight
MarginBottom
SQL Table
<measure code=“SeaWiFS01" name=“SeaWiFS – Reflectance Images - Glob" descr=" SeaWiFS – Reflectance Images - Global">
<data_source service_url="http://capita.wustl.edu/dataservice/data.asmx"/>
<data_facts>< fact_attributes >
<data name ="SeaWiFS" type="map image" descript=“stuff stuff “/>
<granul_query handler_assembly= (access handler)…./>
<fact table, SQL same as CIRA >
</ fact_attributes > … see table left
</ data_facts>
</measure>
NO DIMENSION TABLES
XML Example: SeaWiFS
Geo-referenced Map Image: Time Indexed
Regular Time Series; Fixed Georect; Image Trim
<measure code="TOMS01" name="TOMS - Aerosol Index - Glob" descr="Earth probe TOMS aerosol index">
<data_source service_url="http://capita.wustl.edu/dataservice/data.asmx"/>
<data_facts>< fact_attributes >
<data name ="TOMS" type="map image" descript="/>
<granul_query handler_assembly= (access handler)…./>
<image width=“640" height=“480“ margin_left="69" margin_top="46"/>
< georect lat_ min="-65" lat_ max="65“ lon_min="-180“ lon_max="180“ unit ="DecDeg“ />
</ fact_attributes >
</ data_facts>
<data_dimensions>
<time_dimension
handler_assembly="CAPITA.data.index.impl"
handler_class="CAPITA.data.index.impl.datetime_interval"
start_time="1996-07-25"
end_time="yesterday">
sample_periodicity _unit = "day"
sample_periodicity_mult = “1"
</time_dimension>
</data_dimensions>
</measure>
TOMSFact
TimeIndex Int, Calc from date
DailyImage Img, Parsed from date
LatMin Fixed, -65
LatMax Fixed, 65
LonMin Fixed, - 180
LonMax Fixed, 180
TOMSTime
TimeIndex
DateTime
Virtual Tables (No physical StarTables) XML Example: TOMS
ftp://jwocky.gsfc.nasa.gov/pub/eptoms/images/aerosol/y2002/ea020510.gif
Astronaut Photos: Image IndexedVariable Time, Image Center, Platform SatImg
NASAImageID Universal ID
ProviderURL http://eol.jsc.nasa.gov/
SourceURL http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS004&roll=E&frame=11079
ImageURL http://eol.jsc.nasa.gov/sseop/images/ESC/small/ISS004/ISS004-E-11079.JPG
ProviderAbbrev NASA JSC
ImageDescription Text
Platform ISS004
GeoRegion GUATEMALA
Features SMOKE, GULF OF HONDURAS
DateTime 20020501 212700
Lat 17.6
Lat -90.2
SQL Table
<measure code=“AstroPhoto01" name=“Astronaut Photographs " descr=" Astronaut Photographs ">
<data_source service_url="http://capita.wustl.edu/dataservice/data.asmx"
/>
<data_facts>< fact_attributes >
<data name ="SeaWiFS" type="map image" descript=“stuff stuff “/>
<granul_query handler_assembly= (access handler)…./>
<fact table, SQL same as CIRA >
</ fact_attributes > … see table left
</ data_facts>
</measure>
XML Example: ISS004
Atmospheric Photos: Image IndexedVariable Time, Image Center, PlatformAtmoImg
ImageID Universal ID
ProviderURL http://capita.wustl.edu/capita/people/RHusar/rhusar.html
SourceURL http://capita.wustl.edu/capita/people/RHusar/Pic/9812SanFranciscoAGU/9812SanFranciscoAGU.htm
ImageURL http://capita.wustl.edu/capita/people/RHusar/Pic/9812SanFranciscoAGU/Dcp01000Enh.jpg
Provider Abbrev R Husar
ImageDescription Text
Platform Airplane
GeoRegion NEVADA
Features DUST PLUME
DateTime 19981208 1800
Lat 36.75
Lat -115.15
SQL Table
<measure code=“AtmosPhoto01" name=“Atmospheric Photographs " descr=" Atmospheric Photographs ">
<data_source service_url="http://capita.wustl.edu/dataservice/data.asmx"
/>
<data_facts>< fact_attributes >
<data name ="SeaWiFS" type="map image" descript=“stuff stuff “/>
<granul_query handler_assembly= (access handler)…./>
<fact table, SQL same as CIRA >
</ fact_attributes > … see table left
</ data_facts>
</measure>
XML Example: Dust Plume Photo
DVOY State Maintenance
This DVoyState data structure contains the state variables, which drive DVoy during browsing
It is created by the DataCatalogWarpping service using the Catalog and Wrapping information
User actions on Controllers modify the DVoyState structure directly but do not execute changes
Actions are executed by managers (e.g. ConMan for connections) based on changes in DVoyState
DVoyState resides on the client web page, hence it is unique for each Dvoy session
The session state can be saved as a web page and can be recreated at load time
Workbooks can be created from multiple pages of DVoyState (not yet implemented)
Add New Layer (New): Populate DVoyState.xml
WSGetDatasetListDatasetList.xml DVoyState.xml
WSGetDatasetInfo
DatasetInfo.xml
DatasetSelector
DVoy Catalog Database
On LoadCatalogPage On AddLayer
Init DVoyState Add layer/dataset_abbr to DVoyState Add Layer Description to DVoyState
DVoyState.xml
Event Handling in DVoy
Applications - Examples
Quebec Fires, July 6, 2002
SeaWiFS, METAR and TOMS Index superimposed
SeaWiFS satellite and
METAR surface haze shown in the Voyager distributed data
browser
Satellite data are fetched from NASA GSFC; surface data
from NWS/CAPITA servers
Trans-Atlantic Transport of Quebec Smoke
July 11: Smoke approaching Europe
July 10: Quebec smoke over Mid-Atlantic
SeaWiFS Reflectance
TOMS Absorbing Aerosol
SeaWiFS Reflectance
TOMS Absorbing Aerosol
Spain
Spain
E. US
Web Service Wrapper for TOMS Aerosol Index Fixed Geo-rectangle; Image Trim, daily
TOMS Image Metadata
Geo-rectangle (65, -180; -65, 180)
Image Size (640, 480)
Image Margins (40, 40, 30,30)
Transparent Colors (0,0,255 )
Image Access Metadata
URL template: :ftp://jwocky.gsfc.nasa.gov/pub/eptoms/images/aerosol/YYYYY/eaYYMMDD.gif
StartDate, EndDate
Browsing of Distributed Data from HTTP/FTP Servers
Land Reflectance from SeaWiFS Project, NASA GSFC
AVHRR Oceanic Aerosol
CAPITA, WashU, STL
Fire Pixels, Jan 1997, ESA Ionia Project
Voyager Spatio-Temporal Data Browser
NRL Forecast Model for Dust, Smoke and SulfateMETAR Surface Haze
• Real-time model and surface observations are compared spatially and temporally
Dust
Sulfate
Smoke
METAR HazeTime Selector
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