Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

to track 1% or 0.5% changes was highly desirable. Achieving stability better than 2% required an examination of the mechanisms
affecting stability.
Derived from text
Airborne Equipment; Calibrating; Thermal Stability; Infrared Spectrometers; Optical Filters
20000064545 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA USA
Inflight Validation of AVIRIS Calibration in 1996 and 1997
Green, Robert O., Jet Propulsion Lab., California Inst. of Tech., USA; Pavri, Betina, Jet Propulsion Lab., California Inst. of Tech.,
USA; Faust, Jessica, Jet Propulsion Lab., California Inst. of Tech., USA; Williams, Orlesa, Jet Propulsion Lab., California Inst.
of Tech., USA; Chovit, Chris, 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. 193-203; In English; See also 20000064520; No Copyright;
Avail: CASI; A03, Hardcopy; A04, Microfiche
The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) measures spectral radiance in the solar reflected spectrum
from 400 to 2500 nm. Spectra are measured through 224 spectral channels with nominally 10-nm sampling and 10-nm full width
at half maximum (FWHM). From a NASA ER-2 aircraft flying at 20,000 m altitude, these spectra are acquired as images with
an 11-km width by up to 800-km length. The spatial sampling is 17 m, and the instantaneous field of view (IFOV) 20 m. The objective
of AVIRIS is to acquire calibrated spectra that are used to derive properties of the Earth’s land, water, and atmosphere for
scientific research and environmental applications. to achieve this objective, the AVIRIS spectra must be calibrated. The AVIRIS
sensor is calibrated in the laboratory before and after each flight season, however, the spectra acquired by AVIRIS for science
investigators are acquired in the Q-bay of the ER-2 at 20 km altitude. The objective of the AVIRIS inflight calibration experiment
is to validate the calibration of AVIRIS spectral images in the low pressure, low temperature operating environment of the ER-2.
Inflight calibration experiments have been orchestrated for AVIRIS in every year of flight operations.
Derived from text
Airborne Equipment; Calibrating; Imaging Spectrometers; Infrared Spectrometers; Radiance; Spectrum Analysis; Spectral Signatures
20000064546 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA USA
On-Orbit Calibration of ADEOS OCTS with an AVIRIS Underflight
Green, Robert O., Jet Propulsion Lab., California Inst. of Tech., USA; Pavri, Betina, Jet Propulsion Lab., California Inst. of Tech.,
USA; Boardman, Joseph W., Jet Propulsion Lab., California Inst. of Tech., USA; Shimada, Masanobu, Jet Propulsion Lab., California
Inst. of Tech., USA; Oaku, Hiromi, 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. 205-212G; See also 20000064520; No
Copyright; Avail: CASI; A03, Hardcopy; A04, Microfiche
The Ocean Color Temperature Scanner (OCTS) onboard the Advanced Earth Observation Satellite (ADEOS) was launched
on August 17, 1996. Calibration of OCTS is required for use of the on-orbit measured data for retrieval of physical properties of
the ocean. In the solar reflected portion of the electromagnetic spectrum, OCTS measures images with nominally 700-m spatial
resolution through eight multispectral bands. The objective of this research was to establish the absolute radiometric calibration
of OCTS on orbit through an underflight by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). AVIRIS is a NASA
Earth-observing imaging spectrometer designed, built and operated by the Jet Propulsion Laboratory (JPL). AVIRIS acquires data
from 20-km altitude on a NASA ER-2 aircraft, above most of the Earth’s atmosphere. AVIRIS measures the solar reflected spectrum
from 370 nm to 2500 nm through 224 contiguous spectral channels. The full width at half maximum (FWHM) of the spectral
channels is nominally 10-nm. AVIRIS spectra are acquired as images of 11 km by up to 800 km extent with 20-m spatial resolution.
The high spectral resolution of AVIRIS data allows direct convolution to the spectral response functions of the eight multispectral
bands of OCTS. The high spatial resolution of AVIRIS data allows for spatial re-sampling of the data to match the ADEOS sensors
spatial resolution. In addition, the AVIRIS high spatial resolution allows assessment of the scaling effects due to environmental
factors of thin cirrus clouds, sub-pixel cloud cover, white caps, ocean foam, sun-glint, and bright-target adjacency. The platform
navigation information recorded by AVIRIS allows calculation of the position and observation geometry of each spectrum for
matching to the OCTS measurement. AVIRIS is rigorously characterized and calibrated in the laboratory prior to and following
the flight season. The stability and repeatability of AVIRIS calibration have been validated through an extensive series of inflight
calibration experiments. In the OCTS portion of the spectrum, using pre- and post-flight runway calibrations of AVIRIS coupled
with the on-board calibrator an absolute calibration accuracy of better than 3% spectral, 2% radiometric, and 5% spatial, has been
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