Spectral irradiance measurements using a novel spectroradiometer

Abstract

A novel design of a spectroradiometer has been implemented and tested in the sea to measure underwater optical and physical properties. The spectroradiometer has two high resolution diffraction-based spectrographs assembled back to back in a aluminium alloy casing. The spectrographs employ 512 element photodiode arrays to measure downward (Ed) and upward (Eu) spectral irradiance in the wavelength region 350-750 mm at minimum practical resolution of 2 nm using 50 mu entrance slits. Apart from the optics, the radiometer measures temperature, depth and tilt of the instrument package. State-of-the-art electronics, software and some test results of the instrument are discussed