Data access services
The GENESIS Data Access Services provide the Web Service Technology that allows accessing a variety of different data types over the Web using standardized protocols. The following components can be distinguished:
The Earth Observation (EO) and Coverage Data Access Services allow accessing multi-dimensional coverage (raster) data over the Web using the OGC Web Coverage Service (WCS) protocol. In addition rendered map representations of this coverage data are made available through the Web Map Service (WMS) protocol hereby also supporting temporal, elevation and other dimensions. To meet the GENESIS requirements, existing Open Source technology is extended for publishing such multi-dimensional data retrieved from GeoTIFF or netCDF datastores with varying composition. Support for the WMS 1.3.0 protocol has also been added in the frame of the GENESIS project
The In-Situ Data Access Services allow accessing Observations and Measurements (O&M) through the Sensor Observation Service (SOS) protocol. In addition to data retrieval, it also allows the insertion of observation data which is employed for storing processing results of a Web Processing Service (WPS) as well as for archiving observations made by humans. The work performed within GENESIS has contributed to the development of the SOS 2.0 specification, i.e. the newly developed SOAP binding.
The Geographic Feature data Access Services are Direct Access Download Services for vector data and they are implemented using the Web Feature Service (WFS) protocol. In addition rendered map representations of this vector data are made available through the WMS protocol with support for the time dimension. HTTP POST (WFS) and HTTP GET (WMS) are supported in addition to SOAP. SOAP is implemented to allow applying the GENESIS User Management Solution in conjunction with these data access services. The SOAP Bindings are implemented using the proposals formulated by the INSPIRE SOAP Primer within a Proxy (or Facade) component. An executable test suite for such bindings has also been developed and the findings are given in the GENESIS Report On Standards.
Within the Non Geodata access services a web-based tool is developed to allow the design of complex data models by non-expert users. The tool allows to design the data model and to instantiate a Web Feature Service and a corresponding datastore to publish this type of data. Such a web service instance implements the WFS-T specification with SOAP bindings. The modern web-based GUI allows drag and drop of model components and sharing of data models with peers. Note that this tool has been extended to also support geographic features with point, linestring and polygon geometries.
Finally the Archive and Resource Management Service provides functionalities to consistently manage data resources and their associated metadata. Data that is sent to the ARMS Services may be published onto FTP or HTTP sites or pushed to one of the data access services mentioned above. Upon ingestion of the data, metadata may be extracted and published to one of the Catalogue services. This ARMS service is used when users of the GENESIS Portal upload data sets for processing, for the management of processing results and finally for the automatic ingestion of data that may be provided asynchronously to the ARMS which stores the file in a predefined location.
