Dimensional Analysis applied to Spectrum Handling in Virtual Observatory Context

The handling of units in an automated way by software systems can be a cumbersome procedure when the units are parsed as strings. Software systems parsing units have to take into account extensive tables of unit names, not always identical between different standards. In the Virtual Observatory context, the transfer of metadata in access protocols is specially critical for the understanding of the content of the data (many of which are legacy data). Driven by this issue, we present a way to handle units automatically which is based in dimensional analysis considerations. Although the approach presented here can be valid to any other branch of physics, we concentrate mainly in the application to spectrum handling in the VO context, and show how the proposed solution has been implemented in the VOSpec, a tool to handle VO-compatible spectra.