This joint work reflects on the use of Semantic Web languages for geospatial Web Service compositions in comparison two the classical mainstream Business Process Execution Language (BPEL). We particularly considered the Web Service Modeling Ontology (WSMO) as a tool for implementation. WSMO provides the European counterpart to the American OWL-S, it proved powerful in general web service executions and we revealed drawbacks in handling large amounts of geospatial data.

This contribution to the International Symposium on Spatial Data Quality (ISSDQ) reflects about the uncertainty of geospatial information. Especially, classical elements, such as accuracy, completeness and precision, are complemented with error and imprecision regarding the semantics of terms used to represent data. This work presents, for the first time, a complete categorization of possible uncertainties at attribute level. In addition, it analyses requirements for reference systems in order t... Read full post

This paper presents the joint work between a group of visiting students from Northern and Southern America, my colleague Eva Klien and myself. We assessed the quality of available catalogues for geospatial data and services, analyzed their drawbacks and recommended an idealized Graphical User Interface. The work complements my previous research activities, because it considers the interoperability between human users and machines.

Following my stay at the JRC, we published a paper about some of our joint work. We investigated the interoperability between existing SDI software components in the context of a cross-national forest fire application. In this context, I was mainly involved in the overall conceptualization of the SDI and the development of a Web Processing Service (WPS), which at the time was only available as specification version 0.4. The service offered algorithms to calculate statistics about burned areas in... Read full post

Complementing the other paper on semantic interoperability, this work focused on the needs of semantic data fusion. We presented first ideas on how to semantically describe sensing results and how to facilitate the integration of data from various sources. In this sense, the paper provides a first attempt to connect the work on sensor instruments and measuring with challenges in schema matching, mapping and transformation.

This paper resulted from a collaborative work between Alexander Walkowski and me, in which we tried to connect our PhD theses. We tired to identify the five big changes/revolutions that Information and Communication Technology (ICT) will undergo in the advent of sensor networks. Although this work has only been presented six years ago, the first revolution (interaction with coverages) has already partially been implemented in the context of the OGC Sensor Observation Service (SOS) and the cascad... Read full post

During a traineeship at the Joint Research Centre (JRC) of the European Commission, I was pointed to the challenges of schema heterogeneity. This paper investigates some of the arising issues in the context of integrating Member State data at European level. It suggests a first approach to analyze existing attributes definitions of diverse data models using a shared domain ontology. Arising possibilities to infer matches are outlined using protected sites as an example. This publication provides... Read full post

Coming from first analysis on the semantics of sensor results (performed during my diploma thesis), this paper provides initial investigations on interoperability in the Sensor Web. It provides a brief overview of the relatively novel Observation and Measurements (O&M) standard of the Open Geospatial Consortium (OGC), outlines problems on defining the semantics of sensing results, and points to the few related ontologies, which were available at that time. Although progress has been made, ma... Read full post

This publication resulted from my diploma thesis, which I wrote in a tandem with Arnd Sahlmann. We tried to understand the difference between what is not the ‘classical’ Semantic Web approach of describing processing components and the approach of algebraic specifications coming from standard software engineering. Compared to logic-based reasoning, functional specifications provide a handy alternative to formal modeling. Functional programming languages (such as Haskell) make the spe... Read full post

In 2003, I had my first publication (German only). It presented the outcomes of a study project, where we developed a Spatial Data Infrastructure (SDI) including services for the prediction of gas dispersion and emergency routing. By the time, only few standard Geospatial Web Services were available. Nevertheless, we could prove a solution for stateless chaining.