Submersible Ice Spectroradiometer

Measuring light transmission through sea ice in artic regions is important to the understanding of the biological potential, the regional heat and mass balance, and for the investigation of possible through-ice communications. Past measurements have been made with a submersible scanning spectroradiometer. In this study a design will be developed for a two-spectrometer instrument to measure simultaneously the surface irradiance with a standard cosine receptor and the underice irradiance by means of submersible cosine receptor-fiberoptic bundle coupled to the surface spectroradiometer. Three types of underwater cosine receptors will be tested. A modifcation to an existing PSII spectroradiometer will be made to accommodate a CCD area array detector, and temperature sensitivity to -30 degrees C will be measured. Scattered light measurmeents will be carried out on an existing LabSpec to test the holographic grating order separation filter combination for light leakage. An absorption filter will be specified to reduce the peak sensitivity region of the array to increase the dynamic range at short and long wavelength. An investigation will be made to define the best method to maintain a one hour battery charge life in temperatures reaching -30 degrees C. The Phase I study will last for six months.