Interoperable sharing and visualization of geological data and instruments: preliminary results

On a global scale, different governmental agencies implemented dedicated Spatial Data Infrastructures (SDI) to publish geological, geotechnical and geothematic maps, datasets and metadata. In most cases, the geoportals of SDI use different types of both visual and textual representation of the information and the geological data of each nation are structured in a different way. Moreover, geoportals usually miss information on geological instruments and, often, the data collected directly from these instruments. To enable an interoperable sharing of geological and geothematic maps and data, international and national geoportals mainly adopt the Open Geospatial Consortium (OGC) standards and recommended services, such as Web Map Service, Styled Layer Descriptor, Web Feature Service, Web Coverage Service and Catalog Service for the Web; this methodology however, is still lacking in the harmonization of data and their visualization. This gap, for geological and geomorphological maps and data, was removed by developing two models: GeoSciML (Sen et al., 2005) and GeoSciML- Portrayal (Richard et al., 2012) that also allow a semantic enrichment through the use of thesauri. Anyway, description and sharing of measuring instruments still missing while this capability is given by Sensor Metadata Language standard (SensorML) (Boots et al., 2007). In relation to data sharing from instruments a chance is given by Observations and Measurements standard (O&M) (Cox, 2003). Links between O&M and GeoSciML are widely recognized in relation to delivery of geological sampling and analytical data (Richard et al., 2012). Standardized common interfaces, schema, and syntax for information en-coding is a fundamental requirement for SDI. As discussed, GeoSciML and GeoSciML-Portrayal meet these requirements for Geological and Geomorphological Maps and O&M allows to add geological sampling and analytical data. Exploiting controlled vocabulary resources is a step forward in the full realization of interoperability at the semantic level. Anyway, description and sharing geological and geotechnical instruments information is still missing, though this additional information can enable quality control procedures and improve data comparison. To tackle this gap we tested, a preliminary SensorML modeling, in eXtensible Markup Language, for geological (coring tools) and geotechnical (dynamic penetrometers) instruments defining, for each instrument: identification-code, sensor type, manufacturer and output parameters. Sensor type and outputs parameters definition have been borrowed from the terms present in the "Italian Thesaurus of Earth Sciences", (ThIST), in order to harmonize and semantically enrich metadata. The test proved that SensorML has the capabilities to share semantically enabled information about these instruments in a distributed SDI and view them in a geoportal. It is worth noticing the need for the development of graphical user interfaces for editing SensorML for geological and geotechnical instruments; a solution is offered by the EDI metadata editor (http://edidemo.get-it.it); future works will prepare EDI templates for geological and geotechnical domains.