Imaging Spectroscopy and the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

The airborne visible/infrared imaging spectrometer (AVIRIS)

Green vegetation, nonphotosynthetic vegetation, and soils in AVIRIS data

A method for the radiometric correction of wide field-of-view airborne imagery has been developed that accounts for the angular dependence of the path radiance and atmospheric transmittance functions to remove atmospheric and topographic effects. The first part of processing is the parametric geocoding of the scene to obtain a geocoded, orthorectified image and the view geometry (scan and azimuth angles) for each pixel as described in part 1 of this jointly submitted paper. The second part of the processing performs the combined atmospheric/ topographic correction. It uses a database of look-up tables of the atmospheric correction functions (path radiance, atmospheric transmittance, direct and diffuse solar flux) calculated with a radiative transfer code. Additionally, the terrain shape obtained from a digital elevation model is taken into account. The issues of the database size and accuracy requirements are critically discussed. The method supports all common types of imaging airborne optical instrument...

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Geo-atmospheric processing of airborne imaging spectrometry data. Part 2: Atmospheric/topographic correction

An operational software program is now available for deriving 'scaled surface reflectances' from spectral data collected by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). The program simulates both the atmospheric scattering and absorption effects. Brief descriptions of the algorithm, inputs, outputs, the limitations of the software, and procedures for obtaining the software are given.

Software for the derivation of scaled surface reflectances from AVIRIS data

A comparison is made between two ground-based atmospheric water-vapor measurement techniques, each of which uses data from a solar-pointing radiometer. One technique uses visible wavelength channels to retrieve aerosol loading, surface pressure readings for Rayleigh scattering analyses, and the 0.94 micron channel to extract water vapor from the residual of total versus scattering opacity. The other technique requires only the ratio of channels centered at 0.94 and 0.87 micron. Results are given for the April 13, 1989 AVIRIS in-flight calibration.

In-situ atmospheric water-vapor retrieval in support of AVIRIS validation

Through an in-flight calibration experiment at Rogers Dry Lake, California on September 20, 1989, the radiometric and spectral properties of AVIRIS were determined. In-flight spectral channel positions and the spectral response function in 10 regions of the AVIRIS spectral range, taking in all four spectrometers, are shown to agree closely with the corresponding parameters measured in the laboratory. The intraflight stability for the Rogers Dry Lake calibration site is better than 2 percent with the exception of the strong atmospheric water absorptions where the measured radiance is close to zero. This experiment has provided both direct generation of an in-flight spectral and radiometric calibration and validation of the laboratory calibration at the reported level accuracy.

In-flight validation and calibration of the spectral and radiometric characteristics of the Airborne Visible/Infrared Imaging Spectrometer

AVIRIS is a science research imaging spectrometer that measures radiance in 224 channels between 400 to 2450 nm in the electromagnetic spectrum. To determine the inflight spectral and radiometric characteristics of AVIRIS a validation and calibration experiment was performed. Five data sets were acquired over a calibration site on the homogeneous playa of Rogers Dry Lake, California, U.S. Surface reflectance, atmospheric optical depths, and atmospheric water vapor measurements were acquired concurrently with the overflights. These in situ measurements were used to constrain the LOWTRAN 7 radiative transfer code to predict the total spectral radiance incident at the AVIRIS aperture. These predicted radiances and the AVIRIS measured radiances were analyzed to validate the inflight characteristics. Inflight spectral channel positions and response functions over the AVIRIS spectral range were derived. Radiometric calibration coefficients were calculated for each channel as well as radiometric accuracy, intraflight stability, and noise equivalent delta radiance.

Determination of the in-flight spectral and radiometric characteristics of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

On 7 Mar 1991, an in-flight calibration experiment was held at the Ivanpah Playa in southeastern California for the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imaging spectrometer Five AVIRIS overflights were acquired of a calibration target designated on the Ivanpah Playa surface At the time of the overflights, the reflectance of the calibration target was measured with a field spectrometer In addition, the atmospheric optical depths and water vapor abundance were measured from a radiometer station adjacent to the calibration target These in-situ measurements were used to constrain the MODTRAN radiative transfer code to model the upwelling spectral radiance incident to the sensor aperture during the overflights Analyses of this modeled radiance in conjunction with the laboratory-calibrated radiance were used to determine the spectral and radiometric calibration of AVIRIS while in flight

In-flight calibration of the spectral and radiometric characteristics of AVIRIS in 1991

https://ieeexplore.ieee.org/iel4/121/3531/00688617.pdf

Atmospheric Water Vapor: Recovery, Validation, And Interpretation Of Measurements Obtained With Airborne Visible/114frared Imaging Spectrometer (aviris)

Gordon Hoover

Papers

In-situ atmospheric water-vapor retrieval in support of AVIRIS validation

In-flight validation and calibration of the spectral and radiometric characteristics of the Airborne Visible/Infrared Imaging Spectrometer

Determination of the in-flight spectral and radiometric characteristics of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

In-flight calibration of the spectral and radiometric characteristics of AVIRIS in 1991

Atmospheric Water Vapor: Recovery, Validation, And Interpretation Of Measurements Obtained With Airborne Visible/114frared Imaging Spectrometer (aviris)