Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

20000064542 NASA Ames Research Center, Moffett Field, CA USA
Issues in Absolute Spectral Radiometric Calibration: Intercomparison of Eight Sources
Goetz, Alexander F. H., Colorado Univ., USA; Kindel, Bruce, Colorado Univ., USA; Pilewskie, Peter, NASA Ames Research
Center, USA; Summaries of the Seventh JPL Airborne Earth Science Workshop January 12-16, 1998; Dec. 19, 1998; Volume 1,
pp. 169-174; In English; See also 20000064520
Contract(s)/Grant(s): 95-B26; NAG5-4447; No Copyright; Avail: CASI; A02, Hardcopy; A04, Microfiche
The application of atmospheric models to AVIRIS and other spectral imaging data to derive surface reflectance requires that
the sensor output be calibrated to absolute radiance. Uncertainties in absolute calibration are to be expected, and claims of 92%
accuracy have been published. Measurements of accurate surface albedos and cloud absorption to be used in radiative balance
calculations depend critically on knowing the absolute spectral-radiometric response of the sensor. The Earth Observing System
project is implementing a rigorous program of absolute radiometric calibration for all optical sensors. Since a number of imaging
instruments that provide output in terms of absolute radiance are calibrated at different sites, it is important to determine the errors
that can be expected among calibration sites. Another question exists about the errors in the absolute knowledge of the exoatmospheric
spectral solar irradiance.
Derived from text
Calibrating; Optical Measuring Instruments; Radiance; Atmospheric Models; Radiometers
20000064543 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA USA
Apparent Surface Reflectance of the DOE ARM SGP CART Central Site Derived from AVIRIS Spectral Images
Green, Robert O., Jet Propulsion Lab., California Inst. of Tech., USA; Summaries of the Seventh JPL Airborne Earth Science
Workshop January 12-16, 1998; Dec. 19, 1998; Volume 1, pp. 175-184; In English; See also 20000064520; No Copyright; Avail:
CASI; A02, Hardcopy; A04, Microfiche
The primary objective of the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program at the
Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) is to acquire in situ and remote sensing data to improve cloud
and atmospheric radiative models and parameterizations. As a consequence of this program, a large number of atmosphere and
surface measurements are being acquired at the ARM SGP CART central site. NASA’s Airborne Visible/Infrared Imaging
Spectrometer (AVIRIS) overflew this site on August 1, 1997. AVIRIS measures the upwelling spectral solar radiance from 400
to 2500 nm at 10-nm intervals. From 20 km altitude, these calibrated spectra are acquired as images of 11 by up to 800 km with
20-by-20 m spatial resolution. These data were acquired at the ARM SGP CART Central Site to first investigate derivation of
atmospheric parameters from the measured spectra, second study the variation of these parameters, and third demonstrate the
inversion of the calibrated radiance spectra to apparent surface reflectance. These objectives have been pursued with AVIRIS data
at other sites for atmospheric water vapor and derivation of apparent surface reflectance.
Derived from text
Parameterization; Remote Sensing; Spectral Reflectance; Surface Properties; Radiance
20000064544 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA USA
Minimum High Fire Temperatures Detected in AVIRIS Spectral Measurements from Brazil in 1995
Green, Robert O., Jet Propulsion Lab., California Inst. of Tech., USA; Summaries of the Seventh JPL Airborne Earth Science
Workshop January 12-16, 1998; Dec. 19, 1998; Volume 1, pp. 185-192A; In English; See also 20000064520; No Copyright; Avail:
CASI; A02, Hardcopy; A04, Microfiche
In August and September of 1995 the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was deployed to Brazil as
part of the NASA Smoke Cloud Aerosol and Radiation experiment in Brazil (SCAR-B). AVIRIS measures spectra from 400 to
2500 nm at 10-nm intervals. These spectra are acquired as images with dimensions of 11 by up to 800 km with 20-m spatial resolution.
Spectral images measured by AVIRIS are spectrally, radiometrically, and spatially calibrated. During the SCAR-B deployment,
AVIRIS measured more than 300 million spectra of regions of Brazil. A portion of these spectra were acquired over areas
of actively burning fires. Actively burning fires emit radiance in the AVIRIS spectral range as a function of temperature. This
emitted radiance is expressed from the 2500-nm end of the AVIRIS spectrum to shorter wavelengths as a function of intensity
and modeled by the Planck function.. The objective of this research and analysis was to use spectroscopic methods to determine
the minimum high temperature of the most intense fires measured in the SCAR-B AVIRIS data set. Spectra measured by AVIRIS
with hot sources have been previously examined for volcanic lava and fires in Brazil.
Derived from text
Forest Fires; Imaging Spectrometers; Infrared Imagery; Radiance; Spectrum Analysis; Remote Sensing; High Temperature
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