Showing papers on "Spectroradiometer published in 1981"

Radiometric performance of the Voyager cameras

Abstract: The Voyager Imaging Experiment provided high-quality data of Jupiter and the Galilean satellites with the two flyby trajectories in March and July of 1979. Moderately accurate radiometric measurements have been made using these data. This paper evaluates the radiometric results and describes the inflight and ground geometric and radiometric correction factors. The radiometric quantities of intensity I and geometric albedo I/F are derived, and scaling factors for each of the filters are tabulated for correcting the 'calibrated' data from the Image Processing Laboratory at JPL. In addition, the key characteristics of both Voyager I and Voyager 2 cameras are tabulated.

Spectral variations of coastal water irradiance as a measure of phytoplankton pigments

Abstract: Spectral irradiance data were collected along the coast of British Columbia, Canada, using a submersible spectroradiometer. The corresponding hydrographic observations show that in general, the surface layer where the irradiance measurements were taken, is a well mixed layer. The spectral variations of the data are interpreted with respect to the changes of chlorophyll α and phaeo-pigment concentrations measured at the same time. Optical properties such as spectral attenuation and back scattering coefficients are estimated from the data. The back scattering coefficient is approximated by an expression obtained from theoretical analysis. For remote sensing applications, the intercomparisons of algorithms of Gordon et al. (1980) and Kim et al. (1980) are presented. The results indicate that a linear form of the relationship is suitable for estimating the amount of chlorophyll α + phaeopigments in the coastal water of the inshore region. This may be explained by the variations of diffuse reflectance...

Solar spectral measurements and modeling

Abstract: A newly developed spectroradiometer for routine measurement of the solar spectra is described This instrument measures the solar spectrum between 300 and 2500 nm in less than 25 min, with 07-nm resolution in the visible and 10-nm resolution in the infrared Many examples of global, direct, and diffuse spectra are illustrated for Bedford, Mass and Golden, Colo The effects of air mass, turbidity, and sun tracking on the spectrum are presented, and radiative transfer modeling capabilities and comparisons between models and between models and experiment are discussed

Fourier approach to absolute spectroradiometry

Abstract: The application of Fourier spectroscopy to absolute spectroradiometry in the visible region is discussed, and a description is given of a quartz birefringent interferometer developed for this purpose. The instrument has been used to measure the spectral transmittance of several broadband filters and to intercompare the relative spectral responsivities of two silicon photodiodes. Preliminary measurements of the spectral transmittance of the interferometer are also presented.

LAPR - An experimental pushbroom scanner

Abstract: A three-band Linear Array Pushbroom Radiometer (LAPR) was built and flown on an experimental basis by NASA, at the Goddard Space Flight Center. The functional characteristics of the instrument and the methods used to preprocess the data, including radiometric correction, are described. The radiometric sensitivity of the instrument was tested and compared to that of the Thematic Mapper and the Multispectral Scanner. The radiometric correction procedure was evaluated quantitatively, using laboratory testing, and qualitatively, by visual examination of the LAPR test flight imagery. Although effective radiometric correction could not yet be demonstrated by laboratory testing, radiometric distortion did not preclude the visual interpretation or classification of the test imagery.