Keynote Lectures

Abstract
Over the past decades airborne laser scanning has been adopted as the technology for the acquisition of dense point clouds. In various countries nationwide point clouds have been established. The presentation will start with an overview over these developments as well as the procedures for quality control in point cloud acquisition. In the recent years dense matching in aerial imagery and Geiger and Single-Photon lidar emerged as alternatives for the traditional linear lidar. Investigations are done to understand the potential of these techniques for the creation of digital terrain models and digital surface models. Updating point clouds is usually done by simply scanning a whole area again. For nationwide point clouds this is costly. Strategies will be discussed to avoid re-scanning of a whole country, but still maintain the quality standards. The last part of the presentation will focus on the creation, use, and updating of nationwide 3D landscape models that were obtained by fusing point clouds with 2D object based geo-information.

Abstract
Huge changes are taking place in the governance of the oceans. The implementation of the UNCLOS agreement is creating new rules in what concerns the national responsibility for large areas of the seafloor. Maritime transportation is continuously increasing as the most cost-effective solution for international trade, creating virtual ocean highways. Growing energy demands, and the need to decarbonize the economy are leading to the installation of large power systems close to the coasts, competing with the traditional uses of the ocean, like fisheries or leisure. During the XX Century marine management was mainly based on a project-by-project or permit-by permit approach (Douvere, 2008), with no explicit incorporation of the interplay between the different values in stake. Marine spatial planning (MSP) is emerging as a tool to support the implementation of an ecosystem approach to marine management, supporting ocean governance. It intends to provide legal certainty and predictability for the public and the private use of the ocean and help to quantify the consequences of alternative management strategies. The development of GIS-based MSP is growing fast but it is still strongly constrained by large gaps in baseline data, time and space heterogeneity between the different data sources, and the limitation of the physical, chemical and biological models to reflect natural processes. Economic and social constraints are also a major question in the decision process and its trade-off with the environmental values is dependent on political strategies. While we are not able to mathematically model the complexity of socio-environmental systems, management decisions cannot be reduced to algorithms to be applied by IT systems. Nevertheless, there is an increase role for spatially-explicit systems as the backbone of the marine management decision systems. The on-going international initiative to define significant Marine Protected Areas is the opportunity to put extra emphasis on the development of spatially explicit systems as the basic infrastructure for adaptive management and public participation.

Abstract
Data exploration is the process where users interact with datasets with one or more possibly intertwined, not necessarily concrete from the beginning goals in mind. In doing that, users may operate in a great variety of interaction modes, applying a great variety of functions on data, ranging from data analysis, cleaning, curation, and discovery, all the way to visualization, wrangling, and (syntactic and semantic) zooming. Next to user-initiated activity, very critical to successful explorations is also system-initiated activity, including background data processing, such as statistical, structural, or usage profiling and, based on that, guiding the user in the form of recommendations for any subsequent activity. In this talk, we present a general framework for data exploration, identify several research challenges that arise in that context, and give the highlights of our effort to address some of these challenges and develop a system that has the appropriate architecture and attempts to incorporate many elements of data exploration in a uniform fashion.