How to Define 3D Geoprocessing Operations for the OGC Web Processing Service (WPS)? Towards a Classification of 3D Operations

In the literature a number of taxonomies are present which categorize the functions of GIS. While such taxonomies used to be more of scientific interest they are now getting more practical relevance due to the adoption of the OGC Web Processing Service (WPS) specification. While this standard currently allows specifying arbitrary geoprocessing functionalities, for ensuring interoperability we argue that more detailed definition of possible functions with their parameters is needed. This would facilitate the development of specific application profiles of the WPS if needed. Further classifications of geoprocessing services would help to identify appropriate functions to be grouped together at a higher level (this could be handled in extended web service registries). The goal of this paper is to start a discussion about appropriate concepts of 2.5D (2D with one additional z-value per x-, y-coordinate) and 3D geoprocessing functions and the different ways to group them – in particular we need to distinguish generic and domain-specific functions. This can lead to the definition of relevant WPS profiles. We propose a general classification for 2.5D and 3D functions which contains groups of general purpose functions. This classification leads to sub-classifications that contain several basic functions for each group of the general classification. In addition to these generic functions we further propose domain specific classifications that contain the most important 2.5D and 3D functions for a specific application area, especially functions that are used only within this field. These domain specific classifications will give access to many important functions of a domain. Therefore this paper gives an overview of the state of art, i.e. existing taxonomies of GIS-functions and discusses a new classification for 2.5D and 3D geoprocessing functions as well as domain specific classifications.