Instrument : Narrow Field of View Zenith Radiometer (NFOV)
The Narrow Field of View Zenith Radiometer (NFOV) is a ground-based radiometer that looks straight up. As implied by the name, the field of view of the instrument is narrow, thus permitting the measurement of the downwelling zenith radiance. The output of the instrument consists of a time series of 1-sec observations of the zenith spectral radiance. The radiance is measured at a wavelength of 869 nm. Data from the instrument have many uses; for example, the internal structure of clouds may be characterized by examining a time series of the radiance data.
The following measurements are those considered scientifically relevant.