Nutrient Sensor for Observing Systems

Physical Sciences Inc. (PSI) will design an optical sensor to provide a cost-effective and ruggedized solution to the detection of nutrient loading for long deployment periods in the ocean environment. The proposed sensor is based on an existing instrument that has been already been developed and has demonstrated the usefulness of using optical methods to determine the nitrate, nitrite, bisulfide and bromide concentrations in the ocean. We propose an alternative optical configuration to provide improved performance both in terms of radiometric accuracy and suitability to the marine environment. Our strategy uses off-the-shelf video technology in conjunction with a number of proven dark mapping, averaging and correction techniques to yield reliable spectral information with high dynamic range. The application uses a single imaging sensor for simultaneous acquisition of excitation source and absorption spectra to provide a lower cost, more compact and rugged instrument which is self-calibrating and involves no moving parts.