A battery‐powered spectroradiometer is described which can be operated either manually or automatically in remote field applications. The probe can be easily maneuvered into restricted environments. The incident spectrum is determined by measuring successively through 16 interference filters transmitting in narrow wavebands from 401–698 nm. Minimum detectable spectral irradiance is 0.002–0.015 µW cm−2 nm−1 and is lowest at longer wavelengths. The instrument can measure with an accuracy of ±5% or less to depths where spectral irradiance is 0.03– 1.2% of surface.