OSCAR Sensor Web Enablement Prototype Presentation to WGISS-24 October 2007 Paul Martin ComSine Limited

Page 2 OSCAR © ComSine Limited, 2007 Introduction OSCAR – On-Line Sensor Control & Access Resource Project under the BNSC Internal Co- operation Program that funds a number of small Exploitation Projects Aimed at allowing UK companies to exploit and contribute to international activities Completed in October 2007

Page 3 OSCAR © ComSine Limited, 2007 OSCAR Concept

Page 4 OSCAR © ComSine Limited, 2007 Project Objectives Work with real-world user partners to understand their requirements and determine focus of the project Build a UK software resource that supports the major aspects of the OGC Sensor Web Enablement specifications Look at the role satellite communications can play in a Sensor Web architecture Provide a live demonstration of the OSCAR framework

Page 5 OSCAR © ComSine Limited, 2007 User Partners Critical Software Portuguese software development company Sensor Web interests: Operational services for fire hazards Hidromod Portuguese technical consulting company Sensor Web interests: Monitoring coastal waters UK Environment Agency Already operating and extensive network of in-situ sensors Sensor Web interests: A need to promote high-level access to their sensors Satamatics UK Satellite Communications Company Suppliers of terminal operating under Inmarsat D+ Sensor Web interests: Oil pipeline monitoring

Page 6 OSCAR © ComSine Limited, 2007 Partner Requirements Feedback Each sees a need for deploying sensors in remote areas with limited or no terrestrial communications coverage. Open standards are an important aspect for their business in both sharing information and reducing the time-to-market for their products. They identified the need to gain high-level access to their sensors as critical. The ability of remotely monitor and control their sensors would enable their business to run more efficiently In support of efforts such as GMES (Global Monitoring for Environment and Security), adopting standards to provide alerts on environmental conditions is critical

Page 7 OSCAR © ComSine Limited, 2007 What We Planned to Build 2 Sensor Nodes (one in UK, one in Australia) Each node will host a representative set of weather station sensors Australia Node will use Satellite Communications over the Inmarsat D+ service UK Node will be directly connected to the Internet via WAN/LAN Implement a subset of the O&M and SensorML XML encodings Describe both sensors and their observations Implement the major elements of the SOS, SAS and WNS web services Obtain sensor descriptions and sensor observations Register to receive alerts for alarming conditions from a sensor

Page 8 OSCAR © ComSine Limited, 2007 OGC SWE Components Observations & Measurements (O&M) XML Encoding compliant with OGC Best Practices Document r4 Subset of the encoding to handle the following observations: Temperature, Rainfall, Wind Speed/Direction, Humidity, Air Pressure Sensor Modelling Language (SensorML) XML Encoding compliant with OGC Implementation Specification r2 Subset of the encoding to describe the following sensor: Weather Station (TechnoLine WS-2300)

Page 9 OSCAR © ComSine Limited, 2007 OGC SWE Components Sensor Observation Service (SOS) XML Encoding compliant with OGC Implementation Specification r1 A web service for describing Sensors and obtaining their Observations

Page 10 OSCAR © ComSine Limited, 2007 OGC SWE Components Sensor Alert Service (SAS) XML Encoding compliant with OGC Discussion Paper A web service that allows a sensor to be monitored for an alarming condition, e.g. temperature exceeds a given value A user may subscribe to receive alerts

Page 11 OSCAR © ComSine Limited, 2007 OGC SWE Components Web Notification Service (WNS) XML Encoding compliant with OGC Best Practices Document Web Service for mediating asynchronously between web services, e.g. Confirmation of a SPS tasking request issuing an alert from an SAS when an alarming condition occurs

Page 12 OSCAR © ComSine Limited, 2007 System Context Sensor Node Laptop PC with Weather Station and WebCam sensors attached via RS- 232 or USB A Data Logger will record observations from sensors at a pre-defined interval Periodically the Sensor Node will send observations via some communications protocol to the OSCAR Server Data Repository Communications via SATCOM and Internet will be demonstrated

Page 13 OSCAR © ComSine Limited, 2007 System Context contd OSCAR Server The OSCAR Server will periodically scan the Data Repository for new observations The Data Loader will load new observations into Data Storage Data Storage will store observations using SWE O&M Data Storage will also store description of the sensor using SWE SensorML

Page 14 OSCAR © ComSine Limited, 2007 System Context contd OSCAR SWE and Client A set of OGC SWE compliant web services accessible over the internet Sensor Observation Service - obtain O&M and SensorML Sensor Alert Service - Monitor sensors for alarming conditions Web Notification Service - alert user of alarming condition & mediate with user for planning requests

Page 15 OSCAR © ComSine Limited, 2007 Satellite Communications Australian Demo Site Satamatics SAT-201 terminal via Inmarsat D+ Sensor Node will load SAT-201 with latest observations Observations are sent via satellite to the LES The MHS (gateway) will retrieve messages from the LES Message Client on the OSCAR Server will use ASPI-XML to look for new observations New Observations are written to the Data Repository

Page 16 OSCAR © ComSine Limited, 2007 WAN/LAN Communication UK Demo Site Sensor Node connected to the internet via a wired Ethernet connection New observations will be sent directly over the internet to the Data Repository (e.g. FTP)

Page 17 OSCAR © ComSine Limited, 2007 Web Services Architecture O&M and SensorML are stored in a PostGres/PostGIS relational database Data exposed to upper layers using Java Data Objects (Object Persistence) Web Service is implemented as Java objects OGC SWE XML requests and responses are marshalled and un-marshalled into objects using Apache XML Beans (Data Binding) Client passes XML requests and responses using SOAP over HTTP Non XML messages handled via Java Servlet, e.g. GetCapabilities

Page 18 OSCAR © ComSine Limited, 2007 Equipment Setup Sensor Node (SATCOM) Weather Station in Torquay, Australia Observations collected on demand by issuing a Forward Message to the Sensor Node via a SAT-201 terminal over D+ Observations packaged into OSCAR Data File (ComSine format) to compress data for transmission via a SAT-201 terminal over D+ to the OSCAR Server Sensor Node (WAN/LAN) Weather Station in South Warnborough, UK Observations collected every 10 minute (stored as an OSCAR Data File) OSCAR Server retrieves observations using an FTP pull

Page 19 OSCAR © ComSine Limited, 2007 Issues We Experienced Complete OGC schemas not available at time of development All schemas were extracted from OGC documentation There were conflicts in namespaces between the different services There were conflicts in the use of GML (v3.1 vs 3.2) and other supporting libraries Sharing of objects between SWE components In some cases similar object definitions were implemented across server namespaces E.g. A different FeatureOfInterest object exists for the SOS and the SAS Standards not yet mature Each implementation of the standard is at a different stage in the OGC lifecycle All (except SensorML) are yet to be release as an Implementation Specification at version 1.0

Page 20 OSCAR © ComSine Limited, 2007 Issues We Experienced There are some missing links in the process chain E.g. When you register a new sensor, there is no reference to adding it to an Observation Offering via an OGC request InsertObservation only allows for a single observation to be added per request This could be a performance bottleneck when a single sensor node wished to communicate several observations There may be an argument for a batch insert option

Page 21 OSCAR © ComSine Limited, 2007 On-Line Demonstrator Plans Weather observations from our UK test site will continue to be uploaded into OSCAR We plan to modify the Australian test site to the WAN/LAN setup which will also load weather observations into OSCAR Access to the OSCAR-SWE services will be made available at the following URL Demonstrator will offer access our implementations of the SOS, SAS and WNS services Very keen to continue work on OSCAR/Sensor Web and would welcome collaboration with others

Page 22 OSCAR © ComSine Limited, 2007 Who We Are ComSine is a UK SME with a wholly owned subsidiary in Australia, ComSine Australia PTY Ltd We specialise software and hardware development in the domains of satellite communications, geographical information, navigation and Earth observation. Particular expertise in application of OGC standards and development of web services/SOAs Customers include: ESA, BNSC, the EC, the GSA, Inmarsat, QinetiQ, SEEDA, LogicaCMG, etc.. Operating from premises in NE Hampshire, UK and Torquay, near Melbourne, Victoria, Australia. Website -