SWE-enabled Applications

During the author’s research he recognised that the SWE framework may lead to a more effective method of controlling sensors in specific applications [149]. As shown in Figure 36, this section identifies the characteristics of WSN applications which have benefited from applying SWE specifications. A number of these projects are outlined below, references are provided for the other applications.

Figure 36 - SWE-enabled Applications [150]

Advanced Fire Information System (AFIS)

AFIS Web Fire Mapper monitors the spread of wildfires in South Africa. AFIS employs the SWE specifications and is an Internet-based mapping tool that delivers locations of active fires in near real- time. As illustrated in Figure 37, for selected regions/countries the user can view an interactive map showing active fires for a specified time period, combined with a choice of GIS layers and satellite imagery. AFIS combines in-situ measured sensor data (e.g. from weather stations) and remote sensing data to detect wild fires in South Africa. As soon as the power supply infrastructure (power lines or pylons) is endangered, an automatic notification of responsible persons is triggered so that damage to transformers can be prevented [151].

Figure 37 - AFIS - Sensor Web Fire Mapper Architecture [152]

Key actions of the specifications are summarised below:

Fusion of satellite / weather data / GeoDatabase / traffic data -> compiled by experts at data centre and sent to AFIS / end user SOS used for satellite / weather / traffic / persistent / data SAS used for fire detection (AFIS)

WCS used for location data (GeoDatabase)

WNS used to send alerts to end users (web browser or mobile phone)

OOSTethys (Marine)

OOSTethys are using SWE to conduct Ocean Science Interoperability Experiments (OCEANS IE) in order to implement an earth-observing “system of systems”. Ocean Observing System Architecture has developed software components to leverage oceanographic research. As shown in Figure 38, the aim has been to integrate heterogeneous ocean observing systems such as the application oriented Integrated Ocean Observing System (IOOS) and the research-oriented Ocean Observatories Initiative (OOI) by utilizing SWE and other standards.

OOSTethys partners develop, test and implement easy-to-use, open-source, OGC-compliant software, and have created a working prototype of networked, interoperable, real-time data systems. The goal of the ocean-science community is to develop capabilities that will advance and support initiatives such as the IOOS, ORION, GEOSS, etc. OOSTethys is a provider-to-user data systems framework, using interoperable standards, such as SWE’s SOS to enable discovery and use of data. Software toolkit generates SensorML on-the-fly by getting the capabilities of sensors.

Figure 38 - OOSTethys - Ocean Observing System Architecture [153]

Earth Observation by NASA

NASA Sensor Web application employs SWE-enabled Earth Observation (EO) technologies. EO-1 aims to understand how physical phenomena (e.g. volcanic eruptions) evolve over time (Figure 39). To achieve this purpose, multiple sensor observations over the duration of the event are required. A Sensor Web approach offers the ability to trigger the imaging of these transient events via in-situ sensors and global-coverage, lower-resolution, on-orbit assets to capture higher temporal, spatial and spectral resolution images.

Figure 39 - NASA Sensor Web [154]

Galileo Satellite by ESA

The European Space Agency’s Galileo is a Global Navigation Satellite System (GNSS) and the European competitor to the US Global Positioning System (GPS). The Galileo project promises to bring a range of location-based services to many industries. Combining sensor data, geospatial databases and a geospatial context can provide a foundation for future industry. “The final constellation of Europe’s Galileo satellite navigation system will consist of 30 satellites” [155] and [156].

CSIR Meraka Institute

ICT for Earth Observation (ICT4EO) Research Group is focused on the potential of SWE and has demonstrated a SWE-enabled robotic camera. The Sensor Web is an emerging technology trend that promises to revolutionise Earth Observation [157]. Their research is relevant in the context of Global Earth Observing System of Systems (GEOSS) / South African Earth Observation Strategy (SAEOS) architecture. Meraka are working closely with the OGC and the outcome of SWE will be a global network of interoperable sensors and sensor networks (The Sensor Web). The Sensor Web proves viability of advanced spatial data infrastructure (SDI) [158]. Meraka’s research is directed at developing intelligent middleware to harvest meaningful information from the Sensor Web. They have investigated how semantic reasoning and knowledge representation can be used to configure the Sensor Web to observe particular phenomena.

Corridor Sensor Web

A simplified technology demonstrator of a sensor web has been created by Meraka. A sensor web is an advanced SDI that combines data from multiple sensors and sensor networks to provide feedback to users and sensors. Built by University of KwaZulu-Natal postgraduate students and researchers, it comprises a LEGO mobile robot (built with off-the-shelf components), active radio frequency ID tags with heat sensors along the corridor, which relay signals to readers placed higher up on the walls and a computer (20m away). As depicted in Figure 40, the corridor sensor web uses an open source, standards-compliant software platform and proprietary development tools by Wavetrend Technologies. The demonstrator shows the effectiveness of a sensor web, albeit on a small scale. “A campus sensor web will allow us to investigate sensor web applications such as intelligent traffic-transport systems in a relatively closed and controlled environment”.

Further Examples of SWE-enabled Projects and Applications

 The SANY project was described earlier in this chapter and incorporated SWE into their architecture that is designed to “provide a quick and cost efficient way to reuse data and services from currently incompatible sensor and data sources” [160];

 Open Standards for Urban Operations GUARD Program (OWS-4) [161];

 Sensor Network Application: Water Catchment Flow Monitoring [162];

 SLEWS - A Sensor-based Landslide Early Warning System [163];

 Location Services, Multi-Modal Tracking and Navigation for emergency response [164];

 GeoSWIFT architecture for ISIES (Intelligent Sensorweb for Integrated Earth Sensing). A Sensor Web for a better crop yielding prediction. All data from open standard-based geospatial web services [165];

 GeoCENs 3D Sensor Web Browser (uses NASA WorldWind open-source e.g. WMS) and GeoCENs 2D Browser - mix n match sensors n data [166];

 Rockyview Well Watch - SWE permits access to same information via two different systems (front-end schemas). OGC specs such as SOS used behind the scene, enables searchable well sensors, e.g. owners upload well readings to monitor water levels, conserve resources, check illegal use, location protected, etc) [167];

 The Igliniit (Trails) Project - Inuit (Eskimo) hunters document life on the trail to map and monitor arctic change [168];

 SWE Loves Android - SOS client for Android smart devices (e.g. choose server and access sensor location and data via Android mobile) [169];

 DLR (German Aerospace Center, Oberpfaffenhofen): Tsunami Early Warning & Mitigation Center [170];

 PULSENet Applications: Atmospheric/Air Quality - Fire Monitoring/Smoke Forecasting

[171];

 SAIC Global SensorWeb Client - General SWE client [172];

 PUCK - IEEE 1451 - SOS, Lead by Tom O'Reilly (MBARI) [173];