The web feature service: transaction standard: an example of prototype implementation

Trabalho de Projecto apresentado como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica

Mejoras en el cliente WFS de gvSIG

Web Feature Service (WFS) es un estándar OGC que permite consultar y recuperar datos vectoriales y la información alfanumérica ligada a los mismos. Al contrario que el WMS que ha alcanzado una gran difusión, son pocos los ejemplos reales de uso de WFS para servir información geográfica. Esta situación es debida probablemente a una serie de problemas no resueltos a la hora de implementar en los diversos clientes SIG dicho estándar. La especificación de WFS necesitaría disponer de un mecanismo de paginación, consistente en poder pedirle al servidor un determinado número de fenómenos a partir de una posición dada. Esta funcionalidad, simplificaría considerablemente la creación de una “caché vectorial” de fenómenos. Actualmente la mayor parte de los clientes SIG hacen un uso muy simple del protocolo WFS, que se limita a realizar peticiones para un área determinada. Del mismo modo gvSIG no dispone de ninguna “caché de fenómenos”, que no es más que un servicio que sirve para almacenar temporalmente algunos fenómenos que ya han sido recuperados mediante una conexión WFS (o en general, mediante cualquier origen de datos vectorial). Frente a esto se planteó la mejora de el acceso a WFS para las próximas versiones de gvSIG, de modo que la aplicación fuera capaz de gestionar una caché de fenómenos de manera que se fuera completando con las diferentes peticiones hechas por las consultas WFS. Cuando un cliente hace una primera consulta WFS la cach se debería rellenar con la información devuelta por el servidor. Al cambiar el extent de gvSIG, lo primero que se tendría que hacer es consultar con la caché si ésta contiene la nueva área. Si la contiene, la caché devolvería los fenómenos y si no la contiene se encargaría de hacer la petición al servidor pero únicamente incluyendo la parte de área cuyos fenómenos no estén cacheados. Se presenta dicho desarrollo que permitirá optimizar el acceso al servicio WFS

An ECOOP web portal for visualising and comparing distributed coastal oceanography model and in situ data

As part of a large European coastal operational oceanography project (ECOOP), we have developed a web portal for the display and comparison of model and in situ marine data. The distributed model and in situ datasets are accessed via an Open Geospatial Consortium Web Map Service (WMS) and Web Feature Service (WFS) respectively. These services were developed independently and readily integrated for the purposes of the ECOOP project, illustrating the ease of interoperability resulting from adherence to international standards. The key feature of the portal is the ability to display co-plotted timeseries of the in situ and model data and the quantification of misfits between the two. By using standards-based web technology we allow the user to quickly and easily explore over twenty model data feeds and compare these with dozens of in situ data feeds without being concerned with the low level details of differing file formats or the physical location of the data. Scientific and operational benefits to this work include model validation, quality control of observations, data assimilation and decision support in near real time. In these areas it is essential to be able to bring different data streams together from often disparate locations.

Integrating the Climate Science Modelling Language with geospatial software and services

Much consideration is rightly given to the design of metadata models to describe data. At the other end of the data-delivery spectrum much thought has also been given to the design of geospatial delivery interfaces such as the Open Geospatial Consortium standards, Web Coverage Service (WCS), Web Map Server and Web Feature Service (WFS). Our recent experience with the Climate Science Modelling Language shows that an implementation gap exists where many challenges remain unsolved. To bridge this gap requires transposing information and data from one world view of geospatial climate data to another. Some of the issues include: the loss of information in mapping to a common information model, the need to create ‘views’ onto file-based storage, and the need to map onto an appropriate delivery interface (as with the choice between WFS and WCS for feature types with coverage-valued properties). Here we summarise the approaches we have taken in facing up to these problems.

Supporting interoperable interpolation: the INTAMAP approach

In many Environmental Information Systems the actual observations arise from a discrete monitoring network which might be rather heterogeneous in both location and types of measurements made. In this paper we describe the architecture and infrastructure for a system, developed as part of the EU FP6 funded INTAMAP project, to provide a service oriented solution that allows the construction of an interoperable, automatic, interpolation system. This system will be based on the Open Geospatial Consortium’s Web Feature Service (WFS) standard. The essence of our approach is to extend the GML3.1 observation feature to include information about the sensor using SensorML, and to further extend this to incorporate observation error characteristics. Our extended WFS will accept observations, and will store them in a database. The observations will be passed to our R-based interpolation server, which will use a range of methods, including a novel sparse, sequential kriging method (only briefly described here) to produce an internal representation of the interpolated field resulting from the observations currently uploaded to the system. The extended WFS will then accept queries, such as ‘What is the probability distribution of the desired variable at a given point’, ‘What is the mean value over a given region’, or ‘What is the probability of exceeding a certain threshold at a given location’. To support information-rich transfer of complex and uncertain predictions we are developing schema to represent probabilistic results in a GML3.1 (object-property) style. The system will also offer more easily accessible Web Map Service and Web Coverage Service interfaces to allow users to access the system at the level of complexity they require for their specific application. Such a system will offer a very valuable contribution to the next generation of Environmental Information Systems in the context of real time mapping for monitoring and security, particularly for systems that employ a service oriented architecture.

Utilização das normas de interoperabilidade do Open Geospatial Consortium nos organismos da Administração Pública em Portugal

Com o crescimento da Internet como plataforma global para partilha de informação, cresceu também a diversidade de tipologias de informação a ser partilhada e consultada, nomeadamente informação geográfica. Neste âmbito surge como preocupação a interoperabilidade entre sistemas permitindo que sistemas diferentes possam “comunicar”, partilhando informações e recursos. O presente trabalho propõe-se recolher informação sobre a utilização das normas de interoperabilidade do Open Geospatial Consortium (OGC) na Administração Pública em Portugal, permitindo analisar e tirar conclusões relativamente a esta temática, tendo também em conta o seu enquadramento legal nacional.

Edición cartográfica Web WFS/T (Cartomod)

Dada la necesidad de la Agencia Andaluza de la Energía de mantener el callejero del Inventario de Instalaciones Energéticas Municipales (INVIEM) se plantea la necesidad de utilizar un visor web de edición cartográfica con capacidad de edición para poder realizar las actuaciones oportunas sobre la información espacial, para ello se decide la utilización del estándar WFS/T (Web Feature Service Transactional) y la utilización de software libre en todos los niveles del sistema a implementar. Este desarrollo será el comienzo de una migración completa de todo el sistema actual a una plataforma integrada por completo con productos de software libre

Edición cartográfica web WFS/T (Cartomod)

Dada la necesidad de la Agencia Andaluza de la Energía a mantener el callejero del Inventario de Instalaciones Energéticas Municipales (INVIEM) se plantea la necesidad de utilizar un visor web de edición cartográfica con capacidad de edición para poder realizar las actualizaciones oportunas sobre la información espacial, para ello se decide la utilización del estándar WFS/T (Web Feature Service Transactional) y la utilización de software libre en todos los niveles del sistema a implementar. Este desarrollo será el comienzo de una migración completa de todo el sistema actual a una plataforma integrada por completo con productos de software libre

Disponibilização de informação geográfica na administração da região hidrográfica do Alentejo usando WEBSERVICES: WFS sobre GeoServer

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica

Web Processing Services for Forestry and Environmental Applications

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Serviço de visualização de informação geográfica na WEB - A publicação do atlas de Portugal utilizando a especificação WEB MAP SERVICE

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica

How to reduce the causes of call center contact by implementing web self-service at Sonae MC?

This project aims to provide feasible solutions to improve customer´s Help Area at Continente Online. The goal is to increase satisfaction and loyalty by reducing the main causes that lead customers to appeal to Call Center or abandon the website. The pursued solution is the implementation of Web Self-Service and the vision taken is focused not only on providing customers basic help tools but also innovate with international best practices to sustain Sonae MC´s present and future market leader position. Customer´s feedback, costs and impact are taken in consideration to find the best fit for the company.

Diseño y Desarrollo de un cliente Web Processing Service (WPS) para gvSIG

Estudi dels estàndards definits per l'Open Geospatial Consortium, i més concretament en l'estàndard Web Processing Service (wps). Així mateix, ha tingut una component pràctica que ha consistit en el disseny i desenvolupament d'un client capaç de consumir serveis Web creats segons wps i integrat a la plataforma gvSIG.

GIS in the cloud: implementing a web map service on Google App Engine

Many producers of geographic information are now disseminating their data using open web service protocols, notably those published by the Open Geospatial Consortium. There are many challenges inherent in running robust and reliable services at reasonable cost. Cloud computing provides a new kind of scalable infrastructure that could address many of these challenges. In this study we implement a Web Map Service for raster imagery within the Google App Engine environment. We discuss the challenges of developing GIS applications within this framework and the performance characteristics of the implementation. Results show that the application scales well to multiple simultaneous users and performance will be adequate for many applications, although concerns remain over issues such as latency spikes. We discuss the feasibility of implementing services within the free usage quotas of Google App Engine and the possibility of extending the approaches in this paper to other GIS applications.

A Web Map Service implementation for the visualization of multidimensional gridded environmental data

We describe ncWMS, an implementation of the Open Geospatial Consortium’s Web Map Service (WMS) specification for multidimensional gridded environmental data. ncWMS can read data in a large number of common scientific data formats – notably the NetCDF format with the Climate and Forecast conventions – then efficiently generate map imagery in thousands of different coordinate reference systems. It is designed to require minimal configuration from the system administrator and, when used in conjunction with a suitable client tool, provides end users with an interactive means for visualizing data without the need to download large files or interpret complex metadata. It is also used as a “bridging” tool providing interoperability between the environmental science community and users of geographic information systems. ncWMS implements a number of extensions to the WMS standard in order to fulfil some common scientific requirements, including the ability to generate plots representing timeseries and vertical sections. We discuss these extensions and their impact upon present and future interoperability. We discuss the conceptual mapping between the WMS data model and the data models used by gridded data formats, highlighting areas in which the mapping is incomplete or ambiguous. We discuss the architecture of the system and particular technical innovations of note, including the algorithms used for fast data reading and image generation. ncWMS has been widely adopted within the environmental data community and we discuss some of the ways in which the software is integrated within data infrastructures and portals.