Field Spectroscopy Metadata System Based on ISO and OGC Standards

Field spectroscopy has undergone a remarkable growth over the past two decades in terms of use and application to different scientific disciplines. This work presents an important step forward to improve the interoperability for the spectral library interchange in the field spectroscopy scientific community, by establishing an XML-based metadata system using published International Organization for Standardization (ISO) standards and Open Geospatial Consortium (OGC) specifications. The proposed methodology is structured using three different XML files: each spectral library file acquired during a field campaign is accompanied by an XML file encoded according to the ISO 19156 standard, which carries the information related to the material or surface measured and the sampling procedure applied; the spectral libraries acquired on the same date share an XML file encoded according to the ISO 19115 standard, to represent dataset-level metadata; finally, all of the spectral libraries for the entire field campaign are referenced to an XML file encoded according to the Sensor Model Language (SensorML) specification, for information related to the field spectrometer characteristics and status. This structure ensures that the ISO 19156 files are not very large and avoids the repetition of many common metadata elements required to describe the dataset and sensor description.