Extensible earth observation data catalogues with multiple interfaces

Earth observation data products must be made available for a growing number of user groups. In general access to this data is provided through catalogues enabling searching for products, retrieving their metadata, providing order options and ordering them. One challenge of designing catalogues is to address the very diverse demands of a broad variety of users. Beneath referring to the graphical user interface, those demands include at a major extend the need of integrating or combining the functionalities of specific catalogues into external systems, requiring catalogues to provide accessibility through a variety of protocols like CIP, SOAP, OpenGIS, etc. Further catalogues must be extensible to support future missions and therefore new types of products including new metadata structures. At least the functionalities for ordering products must be generic to be adaptable for future requirements as well. <br><br> This paper gives a more detailed overview about the challenges going along with designing catalogue implementations and describes a generic structure applicable for new catalogues considering the earth observation data catalogue EOWEB® (Earth Observation on the WEB) provided by the DLR as a reference implementation. The focus will be the modelling of metadata structures and the generation of protocol specific functionality for accessing the metadata of products directly without a protocol translation. Further this paper will show up possibilities for providing protocol independent order option retrieval mechanisms and ordering facilities. At least there will be a short discussion concerning the technologies currently used in EOWEB® and possible substitutions.