The aim of this WP is to improve the metrological capability of FSI based techniques beyond the state-of-the-art by removing the current accuracy limitation of the necessary gas cell frequency standard through improved spectroscopy.

In Task 1.1,  several partners will build multiple systems which are capable of measuring, with high accuracy (ideally a few parts in 10⁹) the optical absorption spectrum of the HCN molecule in the region 1527 nm to 1563 nm.

In Task 1.2, partners will perform multiple, independent measurements of absorption spectra of the HCN molecule using the 3 set-ups systems developed in Task 1.1, and publish this data in the open literature.