OGC Consensus: How Successful Standards Are Made

The objective of this project is to evaluate existing and emerging Open Geospatial Consortium (OGC) standards for use in LLNL programs that rely heavily on geographic data. OGC standards are intended to facilitate interoperability between geospatial processing systems to avoid duplication of effort, lower development costs, and encourage competition based on improved capability and performance rather than vendor lock-in. Some of these standards appear to be gaining traction in the geospatial data community, the Federal government, DOE and DHS. A serious evaluation of this technology is appropriate at this time due to increasing interest and mandated compliance in the Federal government in some situations. A subset of OGC standards is identified and reviewed with a focus on applications to LLNL programs. Each standard or recommendation reviewed was evaluated in general terms. In addition, for specific programs such as Gen&SIS and NARAC, a specific evaluation was made of several of the standards and how they could be used most effectively. It is also important to evaluate the acceptance of these standards in the commercial arena. The implementation of OGC standards by the largest GIS vendor (ESRI) was reviewed. At present, OGC standards are primary useful in specific situations. More generally, many of the standards are immature and their impact on the government and commercial sectors is unclear. Consequently, OGC and related developments need to be observed. As specific standards or groups of standards mature and establish their relevance, these can also be incorporated in LLNL programs as requirements dictate, especially if open implementations and commercial products are available.

In this thesis, concepts for developing Spatial Data Infrastructures with an emphasis on visualizing 3D landscape and city models in distributed environments are discussed. Spatial Data Infrastructures are important for public authorities in order to perform tasks on a daily basis, and serve as research topic in geo-informatics. Joint initiatives at national and international level exist for harmonizing procedures and technologies. Interoperability is an important aspect in this context - as enabling technology for sharing, distributing, and connecting geospatial data and services. The Open Geospatial Consortium is the main driver for developing international standards in this sector and includes government agencies, universities and private companies in a consensus process. 
\n3D city models are becoming increasingly popular not only in desktop Virtual Reality applications but also for being used in professional purposes by public authorities. Spatial Data Infrastructures focus so far on the storage and exchange of 3D building and elevation data. For efficient streaming and visualization of spatial 3D data in distributed network environments such as the internet, concepts from the area of real time 3D Computer Graphics must be applied and combined with Geographic Information Systems (GIS). For example, scene graph data structures are commonly used for creating complex and dynamic 3D environments for computer games and Virtual Reality applications, but have not been introduced in GIS so far. 
\nIn this thesis, several aspects of how to create interoperable and service-based environments for 3D spatial data are addressed. These aspects are covered by publications in journals and conference proceedings. The introductory chapter provides a logic succession from geometrical operations for processing raw data, to data integration patterns, to system designs of single components, to service interface descriptions and workflows, and finally to an architecture of a complete distributed service network.
\nDigital Elevation Models are very important in 3D geo-visualization systems. Data structures, methods and processes are described for making them available in service based infrastructures. A specific mesh reduction method is used for generating lower levels of detail from very large point data sets. An integration technique is presented that allows the combination with 2D GIS data such as roads and land use areas. This approach allows using another optimization technique that greatly improves the usability for immersive 3D applications such as pedestrian navigation: flattening road and water surfaces. It is a geometric operation, which uses data structures and algorithms found in numerical simulation software implementing Finite Element Methods. 
\n3D Routing is presented as a typical application scenario for detailed 3D city models. Specific problems such as bridges, overpasses and multilevel networks are addressed and possible solutions described. The integration of routing capabilities in service infrastructures can be accomplished with standards of the Open Geospatial Consortium. An additional service is described for creating 3D networks and for generating 3D routes on the fly. Visualization of indoor routes requires different representation techniques.
\nAs server interface for providing access to all 3D data, the Web 3D Service has been used and further developed. Integrating and handling scene graph data is described in order to create rich virtual environments. Coordinate transformations of scene graphs are described in detail, which is an important aspect for ensuring interoperability between systems using different spatial reference systems. The Web 3D Service plays a central part in nearly all experiments that have been carried out. It does not only provide the means for interactive web-visualizations, but also for performing further analyses, accessing detailed feature information, and for automatic content discovery.
\nOpenStreetMap and other worldwide available datasets are used for developing a complete architecture demonstrating the scalability of 3D Spatial Data Infrastructures. Its suitability for creating 3D city models is analyzed, according to requirements set by international standards. A full virtual globe system has been developed based on OpenStreetMap including data processing, database storage, web streaming and a visualization client.
\nResults are discussed and compared to similar approaches within geo-informatics research, clarifying in which application scenarios and under which requirements the approaches in this thesis can be applied.
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IoT, EO and the Web are providing ever increasing amounts of geospatial information. In order to access and integrate the data using geospatial and temporal methods, standards are needed. This paper provides a summary of current capabilities and recent advancements in standards from the Open Geospatial Consortium (OGC) that provide these capabilities.

The necessity of open standards for effective sharing and use of remote sensing continues to receive increasing emphasis in policies of agencies and projects around the world. Coordination on the development of open standards for geospatial information is a vital step to insure that the technical standards are ready to support the policy objectives. The mission of the Open Geospatial Consortium (OGC) is to advance development and use of international standards and supporting services that promote geospatial interoperability. To accomplish this mission, OGC serves as the global forum for the collaboration of geospatial data / solution providers and users. Photogrammetry and remote sensing are sources of the largest and most complex geospatial information. Some of the most mature OGC standards for remote sensing include the Sensor Web Enablement (SWE) standards, the Web Coverage Service (WCS) suite of standards, encodings such as NetCDF, GMLJP2 and GeoPackage, and the soon to be approved Discrete Global Grid Systems (DGGS) standard. In collaboration with ISPRS, OGC working with government, research and industrial organizations continue to advance the state of geospatial standards for full use of photogrammetry and remote sensing.

OGC (open geospatial consortium) has developed the implementation specifications especially WMS (Web map service) and WFS (Web feature service) which facilitate GIS data dissemination including the map image distribution for visualization and online GIS data exchange. WPS (Web processing service) is also one of the OGC specifications for processing service which allow GIS functions available on the Internet. This paper reports the implementation and development of WPS which enables user to perform geospatial processing with data requested from another WFS site. Spatial databases are used as spatial engine to carry out the geoprocessing function. Oracle spatial, PostGIS and MySQL are the spatial databases which are tested in this research. WPS request form is adapted by applying SQL statement to be used for calling function from spatial database, and also to simplify and shorten the request form. The result clearly shows the success of implementation of this concept by testing the implemented WPS with available external WFS to get new information through the spatial engine available from the desired databases.

The applications of Geographic Information System (GIS) in the education sector are increasing day by day. The geospatial information can be published, discovered, searched, analyzed, and displayed through webGIS-based applications. Lack of an open source geospatial resource-based platform for data sharing, discovery, and service delivery in the education sector is a critical issue in managing the education of large population in India. The use of open geospatial consortium (OGC) developed open standards for geospatial web services will result in the interoperability of geographic information. In this paper, an interoperable and secure service-oriented architecture (SOA)-based webGIS framework is developed to handle the technical and non-technical issues in the education sector. In this research work, spatial analysis on schools is performed along with the design and development of webGIS framework using SOA, OGC standards, and open source software. The developed webGIS framework, acronym as EduGIS, is interoperable and secure which is implemented for the education sector. The development of webGIS framework is based upon three-tier thin client architecture. The present research work has investigated an optimized adoption of various free and open source software like Quantum GIS, GeoServer, Apache Tomcat, PostGIS, and uDig in different tiers of developed webGIS framework. The interoperability of developed EduGIS ensures that it can be shared across different technologies, data, platforms, and organizations. The development of open source-based webGIS framework will serve as a means of reducing licensing costs in developing countries like India and will promote indigenous technological development for primary education in rural areas.

Open source REST services for environmental sensor networking

Moving Object Databases will have significant role in Geospatial Information Systems as they allow users to model continuous movements of entities in the databases and perform spatio-temporal analysis. For representing and querying moving objects, and algebra with a comprehensive framework of User Defined Types together with a set of functions on those types is needed. Moreover, concerning real world applications, moving objects move along constrained environments like transportation networks so that an extra algebra for modeling networks is demanded, too. These algebras can be inserted in any data model if their designs are based on available standards such as Open Geospatial Consortium that provides a common model for existing DBMS's. In this paper, we focus on extending a spatial data model for constrained moving objects. Static and moving geometries in our model are based on Open Geospatial Consortium standards. We also extend Structured Query Language for retrieving, querying, and manipulating spatio-temporal data related to moving objects as a simple and expressive query language. Finally as a proof of concept, we implement a generator to generate data for moving objects constrained by a transportation network. Such a generator primarily aims at traffic planning applications.

Environmental monitoring and evaluation (M&E) systems are indispensable tools for sustainable land management, especially in dry and fragile ecosystems. The reporting and dissemination of its products and indicators are the key roles to perform their missions. Furthermore, the overall success of such multilateral projects and networks depends on well-organized infrastructures for spatial data management. A spatial data infrastructure (SDI) is an efficient framework to centralize the management of spatial data and information related to multilateral projects for the best sharing and exchange between partners and stakeholders in order to ensure that they are interactively connected to use the data efficiently and in a flexible manner. This paper outlines the work undertaken in partnership between the Geography and GIS Department of the Faculty of Arts, King Abdulaziz University, Saudi Arabia Kingdom, the Geomatics, Earth and Land Settlement Branch of the Department of Geology, Faculty of Sciences of Tunis, Tunis El Manar University, Tunisia, and the Sahara and Sahel Observatory OSS which is an intergovernmental organization, in order to build a Spatial Data Infrastructure (SDI) for the ROSELT/OSS program (Long-Term Environmental Monitoring Observatories Network in the Circum-Sahara of the Sahara and Sahel Observatory). This SDI is entirely developed using Open Source technologies and the extensive suite of OGC (Open Geospatial Consortium) standards and specifications, to enable interoperability among and between its different components.

A multiple models-multiple users group GIS-based decision support system for land use problems

Assessing the status and trends of the environment requires the collection, management and publication of spatially referred observations. Since many years, Long-Term Ecological Research sites in Europe collect ecological data, resulting in long-term data series. Nowadays, advanced software tools can enable discovering, accessing, and distributing collected data in a user friendly way. Based on Open Geospatial Consortium (OGC) standards, Web based Geographic Information System allows access to interoperable distributed repositories of observations. The present paper gives an overview of the methods and solutions proposed and tested in the LIFE+ project EnvEurope for the community of researchers of the Long-Term Ecosystem Research (LTER) Network in Europe. These solutions consist in a straightforward online environment for metadata management and discovery, shaped on the ecological community and its practices; components of a Spatial Data Infrastructure including both a network of repositories deploying observations via OGC SOS (Sensor Observation Service) services and Web user interfaces to access and visualize them. The success of the presented approach is linked to the development and availability of easy to define, ready to use tools, enabling site managers to create their own repositories and services.

Recent advances in web technologies, such as those used by Google Maps (http://maps.google.com), have facilitated the development of more interactive geospatial mapping technologies. The technology behind these mapping tools is known as Asynchronous JavaScript and XML (AJAX), which is aimed at more stable functionality, fast interactivity between servers and clients, and cost-effective data exchanges between the servers behind the scenes. Although Google Maps takes full advantage of this recent technology, there are still many restrictions in terms of customization, source modification, and licensing issues. We propose to use ka-Map (http://kamap.maptools.org/), which is a very powerful tool for customizing user components such as graphical user interfaces (GUI). Ka-Map can be coupled with MapServer (http://mapserver.gis.umn.edu/), which was developed at the University of Minnesota. Since both ka-Map and MapServer are open source web-mapping technologies that are compliant with Open Geospatial Consortium (OGC) standards, application of these tools for water resources management is of great interest.

This article intends to provide an advanced traveller information system based on open geospatial consortium (OGC) standards to perform a fuzzy bi-criteria shortest-path analysis for a multimodal transportation network. To do so, chaining of OGC web services is used to resolve interoperability problems among distributed and heterogeneous resource data. First, a web feature service is assigned to each mode of transportation to gather and convert the data to a standard format, such as geographic markup language. Then, the obtained data are combined to model and construct the multimodal transportation network. Subsequently, a web processing service is designed for performing a fuzzy bi-criteria shortest-path analysis in the multimodal transportation network. Finally, the best routes between the origin–destination pair are presented on a digital map by using a web map service. In the study, among various route-selection criteria, travel time and comfort are considered. To model these criteria, the fuzzy set theory is utilized. By using fuzzy decision tables and a Tsukamoto fuzzy inference system, the desirability of the routes is calculated. The results of comparison among the four travel routes between various origin–destination pairs indicate that the proposed system could be an applicable tool for providing pre-trip information and assisting multimodal travellers under uncertain conditions.

VGI-based spatial data infrastructure for land administration

This work presents the development of an efficient tool for managing, visualizing, analysing, and integrating with other data sources, the deformation time-series obtained by applying the advanced differential interferometric synthetic aperture radar (DInSAR) techniques. To implement such a tool we extend the functionalities of GeoNode, which is a web-based platform providing an open source framework based on the Open Geospatial Consortium (OGC) standards, that allows development of Geospatial Information Systems (GIS) and Spatial Data Infrastructures (SDI). In particular, our efforts have been dedicated to enable the GeoNode platform to effectively analyze and visualize the spatio/temporal characteristics of the DInSAR deformation time-series and their related products. Moreover, the implemented multi-thread based new functionalities allow us to efficiently upload and update large data volumes of the available DInSAR results into a dedicated geodatabase. The examples we present, based on Sentinel-1 DInSAR results relevant to Italy, demonstrate the effectiveness of the extended version of the GeoNode platform.