ShipIR model validation using spectral measurement results from the NATO SIMVEX trial

The ship signature model ShipIR/NTCS has been selected as a NATO standard. In 2001 Norway participated in the SIMVEX field trial arranged by NATO in Canada for validation of this model. The measurements were performed on a research vessel under different meteorological conditions, when the ship was sun illuminated and shaded, and also at night. This paper presents spectral results from our high resolution FTIR spectroradiometer, Bomem DA5. Using in-house software that enables correction of non-ideal properties of the spectroradiometer, we obtained improved absolute precision of calibrated spectra. The FTIR results are most interesting for sources with signatures deviating significantly from blackbody functions, like the ship plume, sun illuminated surfaces and sea and sky backgrounds. Ship surface and sea and sky background results have been compared with ShipIR/NTCS predictions. Results from plume measurements have been compared with simulated spectra, using the FASCODE atmospheric model, and we have estimated the plume temperature and the concentration of the most important IR contributing molecules.