The Interoperability between OGC Services and Grid Environment in EnviroGRIDS Project

Emerging developments in geographic information systems and distributed computing offer a roadmap towards an unprecedented spatial data infrastructure in the climate sciences. Key to this are the standards developments for digital geographic information being led by the International Organisation for Standardisation (ISO) technical committee on geographic information/geomatics (TC211) and the Open Geospatial Consortium (OGC). These, coupled with the evolution of standardised web services for applications on the internet by the World Wide Web Consortium (W3C), mean that opportunities for both new applications and increased interoperability exist. These are exemplified by the ability to construct ISO‐compliant data models that expose legacy data sources through OGC web services. This paper concentrates on the applicability of these standards to climate data by introducing some examples and outlining the challenges ahead. An abstract data model is developed, based on ISO standards, and applied to a range of climate data –both observational and modelled. An OGC Web Map Server interface is constructed for numerical weather prediction (NWP) data stored in legacy data files. A W3C web service for remotely accessing gridded climate data is illustrated. Challenges identified include the following: first, both the ISO and OGC specifications require extensions to support climate data. Secondly, OGC services need to fully comply with W3C web services, and support complex access control. Finally, to achieve real interoperability, broadly accepted community‐based semantic data models are required across the range of climate data types. These challenges are being actively pursued, and broad data interoperability for the climate sciences appears within reach. Copyright © 2005 Royal Meteorological Society.

This paper describes an approach for mediating the differences between the Geospatial domain and the Grid environment and creating an interoperable communication between these two platforms. The interoperability between the Geospatial Web services and the Grid infrastructure is part of the enviroGRIDS project and promises to solve important problems from the Earth Observation field, dealing with processing and storing large amounts of data and performing computationally intensive and complex calculations while achieving high performances. The Geospatial Web services, standardized by the Open Geospatial Consortium are adapted to support different execution flows, both on Web and gLite Grid middleware, to maximize the obtained performances.

Enhance discovery and retrieval of geospatial data using SOA and Semantic Web technologies

Spatial Data Infrastructures often maintain directories of public geospatial Web Services built from Web services listed in their registries. However, registry data may be stale and incomplete because their maintenance depends on service owners. A solution is to back the registry with an active directory, or index, that lists Web services found by a Web crawler focused on geospatial Web services. The problem of the identification of the geospatial nature of a Web service appears when such crawler finds a service described in the Web Services Description Language (WSDL). This paper presents two components required to build an active directory: a crawler focused on Open Geospatial Consortium and WSDL-based Web services, and an unsupervised classifier of geospatial Web services described in WSDL.

Geospatial science is the science and art of acquiring, archiving, manipulating, analyzing, communicating, modeling with, and utilizing spatially explicit data for understanding physical, chemical, biological, and social systems on the Earth's surface or near the surface. In order to share distributed geospatial resources and facilitate the interoperability, the Open Geospatial Consortium (OGC), an industry–government–academia consortium, has developed a set of widely accepted Web‐based interoperability standards and protocols. Grid is the technology enabling resource sharing and coordinated problem solving in dynamic, multi‐institutional virtual organizations. Geospatial Grid is an extension and application of Grid technology in the geospatial discipline. This paper discusses problems associated with directly using Globus‐based Grid technology in the geospatial disciplines, the needs for geospatial Grids, and the features of geospatial Grids. Then, the paper presents a research project that develops and deploys a geospatial Grid through integrating Web‐based geospatial interoperability standards and technology developed by OGC with Globus‐based Grid technology. The geospatial Grid technology developed by this project makes the interoperable, personalized, on‐demand data access and services a reality at large geospatial data archives. Such a technology can significantly reduce problems associated with archiving, manipulating, analyzing, and utilizing large volumes of geospatial data at distributed locations. Copyright © 2008 John Wiley & Sons, Ltd.

A geotagged Short Message Service (SMS), such as those following Open Geospatial Consortium (OGC) Open GeoSMS (OGS) standard, is useful for many applications that require location based services field work. In OGS specification, a geotag is used as a hyperlink for retrieving detail information of given target at given location. This feature meets the interoperation requirements of time-sensitive, location-aware notification and monitoring services. This feature can give service providers to design more various and useful service scenarios, and these requirements make importantly to develop vendor specific Apps for realizing these service scenarios. A design pattern for OGS mobile client Apps will help to develop the Apps with relatively less effort. This paper focuses on a design for an OGS mobile client App and shows a Connector-Translator-Launcher (CTL) flow for smartphone environments. The CTL flow based mobile client App is based on Model-View-Controller (MVC) model. It applies pluggable modules for connecting geospatial services pointed by each geotag and translating geospatial content retrieved from such services. The App displays details information specified by a geotag following the OGS. The Android-based mobile client App was developed for OGC's OGC Web Services, Phase 8 (OWS-8). It was applied as a mobile tracking client in geospatial web service testbed scenarios for the Observation Fusion (Tracking) thread. Two pluggable modules were developed for the scenario application. One is a connector module for connecting to a track server, and another is a translator module for translating track information for displaying on map views.

Large amounts of valuable geosciences data have been collected due to the advances in digital earth technology. How to provide an efficient way through which researchers can easily retrieve desired data to facilitate data analysis and system modeling poses great challenges to the geosciences community. This paper presents a Geo-web services based system aimed to enhance geospatial data searching and visualization. The system provides an interoperable way of searching and accessing high quality geospatial data from multi-source and multi-discipline geographic data repositories through the use of Open Geospatial Consortium (OGC) Web services. It is in conformity with OGC Catalog Service for the Web (CSW) specification to play a "directory" role that permits the registry, discovery and access of geospatial information resources distributing on the Internet. Moreover, by leveraging the Rich Internet Applications (RIAs) technologies, the system enables to seamlessly assemble multiple heterogeneous data from different sources into one single user interface for visualization. Two investigations were made to demonstrate how this system has been used to improve the efficiency of searching and collecting geospatial data for a particular research.

The Open Geospatial Consortium (OGC) web processing service interface specification provides a means to perform web-based processes on distributed geodata and to produce thereby web-based geoinformation. However, the complexity of geodata often requires multiple processing steps. These complex scenarios can be addressed by chaining multiple web processing services to a geo-processing workflow. The Business Process Execution Language (BPEL) as the de-facto standard will be used for these workflows. The special nature of standardised OGC web services has to be taken into account for modelling these workflows. A client is missing which allows the integration of existing OGC web services without specifying additional descriptions such as WSDL documents for all participants in BPEL workflows and thereby bridging the OGC and ‘mainstream’ IT world. This leverages the fully web-based integration of distributed OGC services and data. These facts were the starting point for this study to build a client, which is able to model and execute BPEL-based workflows and to integrate multiple standardised and web-based data and processing services. The applicability of the client for web-based information integration will be demonstrated for a real-time risk management scenario in the context of location-based services.

The Open Geospatial Consortium (OGC) has conducted much work in the past on event-based models and architectures. However, the current OGC standard baseline only supports synchronous web service capabilities, which have insofar primarily addressed the request/reply model, where a client makes a request and the server usually responds synchronously, with either the requested information or a failure. Recently, the OGC Publish/Subscribe 1.0 Standard has introduced an abstract model for publish/subscribe message exchange, a long-awaited building block in the OGC suite of geospatial standards. The publish/subscribe pattern is distinguished from the request/reply one by the asynchronous delivery of messages and the ability for a client to specify an ongoing, persistent expression of interest. In this work, we report on the experimentation of the new OGC Publish/Subscribe 1.0 Standard in the context of the OGC Testbed-12 initiative and related fields of work, particularly in the application domains of Sensor Web and Aviation. We illustrate and discuss the enhancements in comparison to previous OGC service architectures, highlighting the benefits of introducing the PubSub 1.0 Standard into the considered systems and their workflows.

Spatial Data Infrastructures (SDI) have been widely accepted to exchange geospatial data among organizations. Today SDIs main focus lies on the provision of geospatial data in the form of distributed spatial web services, the retrieval through catalogues, and visualization in the form of Web Map Services (WMS). The hypothesis presented in this paper takes SDI's one step further by providing a method to process geodata in an Open Geospatial Consortium (OGC) compliant way into information. Two case studies present the potential of standardized geoprocessing services. In addition, this paper addresses the problem of service chaining by providing a system architecture to implement complex geoprocessing models and workflows based on web services using Web Service Orchestration (WSO). The proposed methods utilize spatial standards provided by OGC, the International Organization for Standardization (ISO) and ‘mainstream IT’ standards provided by the World Wide Web Consortium (W3C) and the Organization for the Advancement of Structured Information Standards (OASIS) to establish a generic web service architecture for providing common geoprocessing capabilities (e.g. spatial algorithms, map algebra, etc.) for usage in SDIs.

Geospatial web services within a scientific workflow: Predicting marine mammal habitats in a dynamic environment

Interoperability is the main challenge on the way to efficiently find and access spatial data on the web. Significant contributions regarding interoperability have been made by the Open Geospatial Consortium (OGC), where web service standards to publish and download spatial data have been established. The OGCs GeoSPARQL specification targets spatial data on the Web as Linked Open Data (LOD) by providing a comprehensive vocabulary for annotation and querying. While OGC web service standards are widely implemented in Geographic Information Systems (GIS) and offer a seamless service infrastructure, the LOD approach offers structured techniques to interlink and semantically describe spatial information. It is currently not possible to use LOD as a data source for OGC web services. In this chapter we make a suggestion for technically linking OGC web services and LOD as a data source, and we explore and discuss its benefits. We describe and test an adapter that enables access to geographic LOD datasets from within OGC Web Feature Service (WFS), enabling most current GIS to access the Web of Data. We discuss performance tests by comparing the proposed adapter to a reference WFS implementation.

Along with the unprecedented data-collecting capability, the higher algorithm accuracy and real-time application requirements, redundant spatial computing model had been implemented. Traditionally these spatial computing models are stored in different application centers. To avoid waste of resource, Grid workflow provides a powerful tool for sharing both remote sensing data and processing middleware. In order to enhance the interoperability of the heterogeneous quantitative remote sensing retrieval model in the Grid workflow environment, we propose a web service based Grid workflow framework to improve this situation. According to the Open Geospatial Consortium (OGC) and web service standards, we implement a prototype of this framework. Through the experiment, we can find that web service can work well with Grid workflow and provide a management ability of remote sensing model. Also this approach can separate the application logic and process logic, providing the interoperability ability both in application and process layers.

Geospatial data, such as 2-D satellite images, 3-D image time-series, or 4-D climate/ocean data, provide important information for Earth Science System research. Standardized communication protocols, such as those established by Open Geospatial Consortium (OGC), help to achieve interoperability between clients and servers. To achieve real interoperability, conformance testing is required to test interface conformance of tools provided by, e.g., the geospatial industry. While such testing poses challenges in itself, it is also of impact how much the specification itself supports testing of implementations. A well-defined service request model is of critical importance to a comprehensive and finite test generation. In this paper, we propose a Request Parameter Relationship Analysis (RPRA) approach on the specification-based service request models. These models are requirement consistent which means the requests derived meet all specified pre-conditions for both service operations and the data provided. The aim of our work is to study how many service requests are needed to test a standardized implementation. This work is part of the development of the new test suite for the WCS 2.0 standard. In this way, an improved interoperability of geospatial coverage web services under evolving implementations is expected in future.

Abstract. This paper presents an investigation into the interoperability of 3D building energy data management, delivery, processing, and visualization via web clients using Open Geospatial Consortium – Application Programming Interface (OGC API) standard-based data models and web interfaces. Specifically, the OGC API – 3D GeoVolumes enable access to 3D city model geometries and semantics on the web, the OGC API – Features support the 2D version of the same geospatial data, the OGC API – Processes are used for CityGML analytics and building energy computation with the SimStadt urban simulation software and the OGC SensorThings API is utilized to manage related spatiotemporal or time-series datasets. The efficacy of this approach has been demonstrated in the OGC Testbed 18 Innovation Program, which highlighted the capacity of OGC API web services to synchronize building energy data and computation results between client and server for the case study of Helsinki, Finland, and Montreal, Canada. The advantages of using OGC API services for 3D building energy data interoperability are discussed, and it is suggested that the use of OGC API be promoted to the general public as well as extended to other domains and on a larger scale in future research.