Geospatial Applications of Sensor Networks Copyright © 2004 CRC Press, LLC In-Situ Sensorweb Prototype Demonstrations for Integrated Earth Sensing Applications P.M. Teillet, A. Chichagov, G. Fedosejevs, R.P. Gauthier, A. Deschamps, T.J. Pultz, G. Ainsley, M. Maloley, and F. Simard Canada Centre for Remote Sensing 588 Booth Street, Ottawa, Ontario, Canada K1A 0Y7 ABSTRACT This paper describes initial steps toward building an integrated earth sensing capability that encompasses both remote and in-situ sensing. Initial work has focused on the demonstration of in-situ sensorweb prototypes in autonomous remote operation in the context of monitoring applications in Earth and environmental science. The paper discusses integrated Earth sensing and sensorwebs, and reports on an in-situ sensorweb prototype demonstration in support of flood hazard monitoring in Manitoba, as well as on development plans for a more advanced, heterogeneous sensorweb in support of drought severity and rangeland/crop vigour monitoring in Alberta. 1. INTRODUCTION: INTEGRATED EARTH SENSING AND SENSORWEBS Our monitoring requirements and responsibilities as nations and as members of the global community continue to multiply. We have some powerful science and technology tools at our disposal but it is not clear that we are using them effectively to tackle the issues before us. In many countries, government agencies in particular have long traditions of excellence in field data acquisition and more recently space-based observations of the Earth. However, such endeavours have been and largely remain resource-intensive activities. Innovative tools need to be developed to provide the time-critical and cost-effective monitoring of complex and dynamic systems essential to support effective decision-making. At the 2002 World Summit on Sustainable Development, the point was made that “… space-derived information generally needs to be combined with in- situ measurements and models to obtain a holistic picture of the Earth’s environment. … There is no Sustainable Development without adequate information about the state of the Earth and its environment” a . Indeed, the a Josef Aschbacher, European Space Agency (ESA). Copyright © 2004 CRC Press, LLC 259 confluence of advanced technologies for Earth-based sensorwebs, b,c,d Earth science satellite webs [1,2], and the power of the Internet will soon provide a kind of global virtual presence [3] or integrated Earth sensing [4,5]. Unlike other distributed sensor networks, sensors in a sensorweb are “smart” enough to share information with each other, modify their behaviour based on collected data, and only report on and/or act on data, aggregates and/or events of interest to the user. In the in-situ context, a “sensorweb” consists of an autonomous wireless network of smart sensors deployed to monitor and explore environments or, more succinctly, “a macro-instrument for coordinated sensing” [6]. With the capability of providing an ongoing virtual presence in remote locations, many sensorweb uses are being considered in the context of environmental monitoring. The work reported in this paper has been undertaken within the framework of a threefold effort to: (1) design and deploy sensorwebs for ground-based in- situ data acquisition, (2) develop methods to assimilate in-situ and remote sensing data into models that generate validated information products, and (3) facilitate the accessibility of in-situ sensor data and/or metadata from on-line geospatial data infrastructures. The focus of recent work has been on the first of these. This paper describes initial steps towards building an integrated earth sensing capability and focuses on demonstrations of an in-situ sensorweb prototype in remote operation in the context of Earth and environmental science applications. As a first application, a five-node sensorweb prototype was deployed and operated autonomously in 2002-2003 in the Roseau River Sub-Basin of the Red River Watershed in Manitoba, Canada as part of a flood hazard monitoring project. Soil temperature, soil moisture and standard meteorological measurements were accessed remotely via landline and/or satellite telecommunication from the Integrated Earth Sensing Workstation (IESW) in Ottawa. Independent soil moisture data were acquired from grab b Pister, K.S.J., Kahn, J.M., and Boser, B.E. “Smart Dust: Wireless Networks of Millimeter-Scale Sensor Nodes”, Highlight Article in 1999 Electronics Research Laboratory Research Summary, Department of Electrical Engineering and Computer Science, University of California, Berkeley, California, 94720 USA, 1999, 6 pages. c Neil Gross, “The Earth Will Don an Electronic Skin”, in “21 Ideas for the 21 st Century”, BusinessWeek online, August 30, 1999. d Wireless sensor networks have been identified recently as one of ten emerging technologies that will change the world. Cf. Roush, W. “Wireless Sensor Networks”, Technology Review (MIT’s Magazine of Innovation), 106(1): 36-37, 2003. Copyright © 2004 CRC Press, LLC 260 GeoSensor Networks samples and field-portable sensors on days when Radarsat and Envisat synthetic aperture radar (SAR) image acquisition took place. The in-situ data enabled spatial soil moisture estimates to be made from the remotely sensed data for use in a hydrological model for the applications at hand. Another project is underway for the development of a more advanced, heterogeneous sensorweb in support of drought severity monitoring in Alberta. 2. PROTOTYPE WIRELESS INTELLIGENT SENSORWEB EVALUATION The Prototype Wireless Intelligent Sensorweb Evaluation (ProWISE) project has targeted the field deployment of a sensorweb with full inter-nodal connectivity and remote access and control. It has also tested remote webcam operations and demonstrated telepresence at remote field sites. These deployments do not yet take advantage of fully miniaturized systems but they utilize commercial-off-the-shelf technology and are taking place in real as opposed to controlled environments. The initial prototype sensorweb test-bed consists of five nodes and a base station/hub. Each node has a compact mast with Adcon e sensors recording temperature, relative humidity, downwelling solar radiation, rainfall, wind direction, wind speed, leaf wetness as appropriate, soil temperature, and soil moisture (Figure 1). e Adcon, http://www.adcon.at/adcon/english/welcome.htm. Figure 1: Fully instrumented ProWISE sensorweb node deployed at Transport Canada Federal Airport site for a groundwater project near Toronto, Ontario. The top end of the soil moisture probe is visible in the foreground. Behind that to the left is the solar panel and in front of the mast is the case containing the MT-2000 satellite transceiver, HC- 12 microprocessor, and batteries. Copyright © 2004 CRC Press, LLC In-Situ Sensorweb for Integrated Earth Sensing Applications 261 Over time, the instrumentation has been augmented by various telecommunication devices, micro-controllers, and other sensors from various vendors. Different wireless telecommunication strategies have been examined. Access and control are Internet web-enabled, remotely operated, and have been tested from the individual nodes to the IESW in Ottawa as well as from the nodes to the hub and then to the IESW. Smart internodal communication is part of the next phase of the ProWISE development in the drought severity monitoring project. 3. FLOOD HAZARD MONITORING: A PROTOTYPE IN-SITU SENSORWEB DEMONSTRATION There are significant urban populations and infrastructures that are vulnerable to flooding in the Red River Watershed. Consequently, there are ongoing studies to enhance the flood protection infrastructure at Winnipeg, Manitoba. Integrated Earth sensing activities that encompass both remote and in-situ sensing will contribute to enhanced flood mitigation, flood forecasting and emergency planning along the Red River, where there exists the potential for multi-million dollar flood disasters. The in-situ sensorweb work described in this paper is part of an effort to produce hazard and infrastructure assessments and improve real-time monitoring capabilities that contribute to reducing the impacts and costs of flood disasters, and improve decision-making during flood emergencies [7]. The ProWISE sensorweb was deployed in the Roseau River Sub-Basin of the Red River Watershed in September 2002 and remained there throughout the winter months and the flood season until the end of June 2003. The five nodes and hub were distributed across an extent of approximately 50 km. The sensorweb operated autonomously and provided soil temperature and soil moisture measurements plus standard meteorological parameters remotely via landline and/or satellite to the IESW at the Canada Centre for Remote Sensing (CCRS) in Ottawa, Ontario. C-band Synthetic Aperture Radar (SAR) data were acquired from the Radarsat-1 SAR (HH polarization) and the Envisat Advanced SAR (ASAR) (HH and VV polarizations) instruments in order to estimate and monitor soil moisture over large areas [8,9]. The in-situ data were used to help generate spatial soil moisture estimates from the SAR image data for use in the WATFLOOD hydrological model for flood hazard monitoring. Initially, the data collected by the soil moisture sensors (C- Probes) were transmitted with the other sensor data via the Adcon A733 wireless radio modems to the Adcon A840 data storage unit and gateway situated at the hub in Shevchenko School in Vita, Manitoba. These data were then transmitted via a modem connection by a landline to the IESW. The C- Probe terrestrial wireless link to the A840 was replaced by a Vistar MT-2000 Copyright © 2004 CRC Press, LLC 262 GeoSensor Networks satellite transceiver link for trial periods (Figure 2). The C-Probe communicated with the MT-2000 via a programmed HC-12 microprocessor. This put each soil moisture sensor from each individual node “on the air” in real time and constitutes an important step in demonstrating different modes of sensorweb deployment. 4. DROUGHT SEVERITY MONITORING: TOWARD A HETEROGENEOUS IN-SITU SENSORWEB DEMONSTRATION Detecting onset of drought and, more generally, predicting and assessing crop growth and rangeland productivity has very important commercial, environmental and community benefits. A new project to test new capabilities for drought severity monitoring in Alberta is focusing on three key components for success: (1) a smart sensorweb that provides autonomous and continuous in-situ measurements and overcomes the spatial-temporal sampling problem; (2) smart vegetation modeling agents that integrate all available relevant information to yield economically and ecologically valuable information; (3) an OpenGIS Consortium (OGC) compliant, Internet-based infrastructure that facilitates communication between sensor nodes and servers and makes the data and services accessible to all who can benefit from them. In this project, the current ProWISE nodes will become the base stations for local-area sensorwebs consisting of many smaller sensor nodes. Thus, hierarchically, there will be at least two levels to the in-situ sensorweb, encompassing different types of sensors and sensor nodes, making it a so- called heterogeneous sensorweb. 5. CONCLUDING REMARKS Earth science sensorweb data have the potential to become an integral part of government policy and decision support domains. The work reported in this paper has taken some initial steps towards demonstrating new approaches to the time-critical and cost-effective monitoring of complex and dynamic systems. Nevertheless, much more needs to be done to provide a more solid basis for issue-specific decision support, including smarter, smaller and cheaper sensor systems for monitoring, the integration of time-critical in-situ sensor data and/or metadata into on-line geospatial data infrastructures, and the generation of validated data and information products derived from the fusion of in-situ and remote sensing data and their assimilation into models. Ongoing challenges in such endeavours include insufficient resources to put in place capabilities for integrated assessment and the potential future shortfall of highly qualified science and technology personnel. Copyright © 2004 CRC Press, LLC In-Situ Sensorweb for Integrated Earth Sensing Applications 263 REFERENCES [1] NASA. Exploring Our Home Planet: Earth Science Enterprise Strategic Plan, NASA Headquarters, Washington, DC, 2000. [2] Zhou, G, Baysal, O., Kafatos, M., and Yang, R. (Editors). Real-Time Information Technology for Future Intelligent Earth Observing Satellites, ISBN: 0-9727940-0-X, Hierophantes Publishing Services, Pottstown, PA, 2003. [3] Delin, K.A. and Jackson, S.P. “The Sensor Web: A New Instrument Concept”, Proceedings of SPIE’s Symposium on Integrated Optics, San Jose, CA, January 2001. (See also http://sensorwebs.jpl.nasa.gov/ resources/sensorweb-concept.pdf) [4] Teillet, P.M., Gauthier, R.P., Chichagov, A., and Fedosejevs, G. “Towards Integrated Earth Sensing: Advanced Technologies for In Situ Sensing in the Context of Earth Observation”, Canadian Journal of Remote Sensing, 28(6): 713-718, 2002. Figure 2: Lo gical data flow of the deployment configuration and satellite telecommunication routing between sensors in the field and the Integrated Earth Sensing Workstation (IESW) in Ottawa. Except for proof-of- concept trials, the hub uses landlines to communicate with the IESW to save costs. Copyright © 2004 CRC Press, LLC 264 GeoSensor Networks [5] Teillet, P.M., Gauthier R.P., and Chichagov A. “Towards Integrated Earth Sensing: The Role of In Situ Sensing”, Chapter 2, pp. 19-30, in Real-time Information Technology for Future Intelligent Earth Observing Satellites, (Eds.). Zhou, G., Baysal, O., Kafatos, M., and Yang, R., ISBN: 0-9727940-0- X, Hierophantes Publishing Services, Pottstown, PA, 2003. [6] Delin K.A. “The Sensor Web: A Macro-Instrument for Coordinated Sensing.” Sensors, 2: 270-285, 2002. (See also http://sensorwebs.jpl.nasa.gov/ resources/Delin2002.pdf) [7] Wood, M.D., Henderson, I., Pultz, T.J., Teillet, P.M., Zakrevsky, J.G., Crookshank, N., Cranton, J., and Jeena, A. “Integration of Remote and In Situ Data: Prototype Flood Information Management System”, Proc. of the 2002 IEEE Geoscience and Remote Sensing Symposium (IGARSS 2002) and the 24th Canadian Symposium on Remote Sensing, Toronto, Ontario, Volume III, pp. 1694-1696. (also on CD-ROM, 2002.) [8] Wigneron, J P., Calvet, J C., Pellarin, T., Van de Griend, A.A., Berger, M., and Ferrzzoli, P. “Retrieving Near-Surface Soil Moisture From Microwave Radiometric Observations: Current Status and Future Plans”, Remote Sensing of Environment, 85(4): 489-516, 2003. [9] Boisvert, J.B., Pultz, T.J., Brown, R.J., and Brisco, B. "Potential of Synthetic Aperture Radar for Large Scale Soil Moisture Monitoring", Canadian Journal of Remote Sensing, 22(1): 2-13, 1996. Copyright © 2004 CRC Press, LLC In-Situ Sensorweb for Integrated Earth Sensing Applications 265 . Sensing”, Chapter 2, pp. 1 9-3 0, in Real-time Information Technology for Future Intelligent Earth Observing Satellites, (Eds.). Zhou, G., Baysal, O., Kafatos, M., and Yang, R., ISBN: 0-9 72794 0-0 - X,. systems but they utilize commercial-off-the-shelf technology and are taking place in real as opposed to controlled environments. The initial prototype sensorweb test-bed consists of five nodes and. by a landline to the IESW. The C- Probe terrestrial wireless link to the A840 was replaced by a Vistar MT-2000 Copyright © 2004 CRC Press, LLC 262 GeoSensor Networks satellite transceiver link