Data exchange between distributed spectral databases

Spectral databases constitute one of the components of a complete observing system, storing in situ spectroscopic measurements plus associated metadata and providing data for the validation, calibration, and simulation of imaging spectrometer products. Such databases may be employed by physically or organisationally separate entities. Consequently, methods for data exchange between distributed spectral databases are required, allowing the transfer of defined subsets of spectral data including their full metadata context from a source to a target system. The data exchange comprises generic approaches to the sequential steps of ordered table row export, relational storage in XML files, and nonconflicting import into the target database. The SPECCHIO spectral database system was used as a test bed for the data exchange between databases of identical schemata and according import/export functionality has been added to the SPECCHIO application. Import and export speeds were assessed using test cases of different metadata space densities, a score for the density with which associated metadata are detailed, and the potential utility as a quantitative rating for quality. Future spectral databases should allow the exchange between heterogeneous systems, ideally implementing a common subset of metadata parameters and thus supporting the long-term usability and data sharing between research partners. (C) 2011 Elsevier Ltd. All rights reserved.