52°North Thin SWE Client

Visualising Time Series Data with

Open Source Components

Simon Jirka & Arne Bröring

(52° North)

FOSS4G 2011, Denver

FOSS4G 2011

• Web-based client for displaying time series sensor data

• Based on OGC Sensor Web standards

• Funded by:

Project Overview

1. EO2HEAVEN: EC FP-7 project

investigating relationships between

health and environment

2. German Federal Waterways

Engineering and Research Institute:

Large operator of hydrological

measurement stations

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Intro: Sensor Web

• World Wide Web is for websites– HTTP

– HTML

– ...

• Sensor Web is for sensors– O&M

– SOS

– SPS

– ...

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Sensor Web Enablement (SWE)

– http://www.ogcnetwork.net/swe

• Web Service interfaces & data encodings

• Used to build a Sensor Web

• Integration of (geo)sensors on application level

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SWE Functionality

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Feature of Interest

Procedure (ID := “DAVIS_123“)

23 m/s 16.9.2010 13:45

Result

uom

Phenomenon TimeObserved Property := “Wind_Speed“

Observation

Observation & Measurements

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Sensor Observation Service

SensorML

Observations &

Measurements

GetCapabilities

RegisterSensor

DescribeSensor

InsertObservation

GetObservation

GetFeatureOfInterestGML

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Aims of the Thin SWE Client Development

• Web-based client

• Visualising time series data

• Compliant to OGC O&M

• Data loading from multiple SOS instances

• Re-use of existing Open Source components

• No Adobe Flash !

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Application Domains

• Hydrology

– PEGELONLINE

– OGC Surface Water IE

• Air quality

– EO2HEAVEN

• Weather data

– Wupperverband

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Functional Requirements

• Diagram view

– Combine multiple time series

– Time series navigation (zoom, pan, first value, last value)

– Overview time series for easier navigation

• Map display show sensor locations

• Data export

– CSV, XLS files containing observation data

– PDF showing the current view

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SOS-Client

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SOS-Client

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SOS-Client

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Re-used Server-side Software Packages

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Re-used Open Source Software

• JFreeChart

– Framework for generating

diagrams

– Offers a broad range of different diagram stlyes

http://www.jfree.org/jfreechart/

• 52°North OX-Framework

– Encapsulating the communication with SOS servers

http://52north.org/oxf

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Re-used Browser-side Software Packages

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Re-used Open Source Software

• Google Web Toolkit

– Used as general framework

– Develop in Java

– Create JavaScript

– Re-use of core elements

• Remote procedure calls (between browser and server

component of the client)

• Internationalisation

• Browser independency

http://code.google.com/webtoolkit/

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Re-used Open Source Software

• SmartGWT

– Based on GWT

– User interface framework

– Large widget library

http://code.google.com/p/smartgwt/

smartgwt

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Re-used Open Source Software

• OpenLayers

– Map view showing the sensor

locations

– Extension of the menu for selecting new sensor data

sets

http://openlayers.org/

– Integration with GWT:

http://gwt-openlayers.sourceforge.net

OpenLayers

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Re-used Open Source Software

• Gimv (Google Web Toolkit Image Viewer)

– User interface components to interact with images

(i.e., charts)

– Provides functionality such as:

• Navigation with a diagram view

• Zooming

• Tool tips

• Overview images (used for an overview diagram)

– No Adobe Flash! Javascript

http://code.google.com/p/gimv/

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Outlook

1. Increase interoperability

2. Usability enhancements

3. Extension to SOS 2.0

• Contributions (ideas, code, and tests with SOS

instances) are welcome!

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Questions?

Thank you!

Arne Bröring

broering@52north.org

http://52north.org/thinSWEclient