Column atmospheric water vapor and vegetation liquid water retrievals from Airborne Imaging Spectrometer data

High spatial resolution column atmospheric water vapor amounts were derived from spectral data collected by the airborne visible-infrared imaging spectrometer (AVIRIS), which covers the spectral region from 0.4 to 2.5 μm in 10-nm bands and has a ground instantaneous field of view of 20×20 m from an altitude of 20 km. The quantitative derivation is made by curve fitting observed spectra with calculated spectra in the 1.14-μm and 0.94-μm water vapor band absorption regions using an atmospheric model, a narrowband spectral model, and a nonlinear least squares fitting technique. The derivation makes use of the facts that (1) the reflectances of many ground targets vary approximately linearly with wavelength in the 0.94- and 1.14-μm water vapor band absorption regions, (2) the scattered radiation near 1 μm is small compared with the directly reflected radiation when the atmospheric aerosol concentrations are low, and (3) the scattered radiation in the lower part of the atmosphere is subjected to the water vapor absorption. The technique is directly applicable for retrieving column water vapor amounts from AVIRIS spectra measured on clear days with visibilities 20 km or greater. The precision of the retrieved column water vapor amounts from several data sets is 5% or better. Based on the analyses of an AVIRIS data set that was acquired within an hour of radiosonde launch, it appears that the accuracy approaches the precision. The derived column water vapor amounts are independent of the absolute surface reflectances. It now appears feasible to derive high spatial resolution column water vapor amounts over land areas from satellite altitude with the proposed high resolution imaging spectrometer (HIRIS). Curve fitting of spectra near 1 μm from areas covered with vegetation, using an atmospheric model and a simplified vegetation reflectance model, indicates that both the amount of atmospheric water vapor and the moisture content of vegetation can be retrieved simultaneously because the band centers of liquid water in vegetation and the atmospheric water vapor are offset by approximately 0.05 μm.

[1]  R. Goody,et al.  A statistical model for water‐vapour absorption , 1952 .

[2]  C. Rodgers,et al.  The computation of infra‐red cooling rate in planetary atmospheres , 1966 .

[3]  W. Malkmus,et al.  Random Lorentz band model with exponential-tailed S-1 line-intensity distribution function , 1967 .

[4]  H. Gausman,et al.  Interaction of Isotropic Light with a Compact Plant Leaf , 1969 .

[5]  H. Condit.  THE SPECTRAL REFLECTANCE OF AMERICAN SOILS , 1970 .

[6]  E. B. Knipling.  Physical and physiological basis for the reflectance of visible and near-infrared radiation from vegetation , 1970 .

[7]  Arthur J. Richardson,et al.  Water and Air Changes in Grapefruit, Corn, and Cotton Leaves with Maturation1 , 1971 .

[8]  F. Volz.  Economical Multispectral Sun Photometer for Measurements of Aerosol Extinction from 0.44 mum to 1.6 mum and Precipitable Water. , 1974, Applied optics.

[9]  Dudley A. Williams,et al.  Optical properties of water in the near infrared. , 1974 .

[10]  Anne B. Kahle,et al.  Mapping of hydrothermal alteration in the Cuprite mining district, Nevada, using aircraft scanner images for the spectral region 0.46 to 2.36µm , 1977 .

[11]  F. X. Kneizys,et al.  Atmospheric transmittance/radiance: Computer code LOWTRAN 5 , 1978 .

[12]  R. Ashley,et al.  Spectra of altered rocks in the visible and near infrared , 1979 .

[13]  W. Mankin.  Fourier transform method for calculating the transmittance of inhomogeneous atmospheres. , 1979, Applied optics.

[14]  C. Tucker.  Remote sensing of leaf water content in the near infrared , 1980 .

[15]  E. R. Stoner,et al.  Physiochemical, site, and bidirectional reflectance factor characteristics of uniformly moist soils. [Brazil, Spain and the United States of America] , 1980 .

[16]  R. D'Entremont,et al.  Improved Cloud Detection Utilizing Defense Meteorological Satellite Program near Infrared Measurements , 1982 .

[17]  C. Prabhakara,et al.  Remote sensing of precipitable water over the oceans from Nimbus 7 microwave measurements , 1982 .

[18]  M. Iqbal.  An introduction to solar radiation , 1983 .

[19]  F. G. Fernald,et al.  Spectral least squares quantification of several atmospheric gases from high resolution infrared solar spectra obtained at the South Pole , 1983 .

[20]  Ed R. Westwater,et al.  A Steerable Dual-Channel Microwave Radiometer for Measurement of Water Vapor and Liquid in the Troposphere , 1983 .

[21]  R. Dickinson.  Land Surface Processes and Climate—Surface Albedos and Energy Balance , 1983 .

[22]  H. Gordon,et al.  Remote Assessment of Ocean Color for Interpretation of Satellite Visible Imagery: A Review , 1983 .

[23]  S. Warren,et al.  Optical constants of ice from the ultraviolet to the microwave. , 1984, Applied optics.

[24]  J. Susskind,et al.  Remote Sensing of Weather and Climate Parameters From , 1984 .

[25]  J. Otterman,et al.  Albedo of a Forest Modeled as a Plane with Dense Protrusions , 1984 .

[26]  J. H. Shaw,et al.  Sources of systematic errors in line intensities. , 1985, Applied optics.

[27]  C. G. Justus,et al.  A Model for Solar Spectral Irradiance and Radiance at the Bottom and Top of a Cloudless Atmosphere , 1985 .

[28]  C. Rinsland,et al.  Identification of atmospheric C(2)H(2) lines in the 3230-3340-cm(-1) region of high resolution solar absorption spectra recorded at the National Solar Observatory. , 1985, Applied optics.

[29]  D. E. Bowker,et al.  Spectral reflectances of natural targets for use in remote sensing studies , 1985 .

[30]  A F Goetz,et al.  Imaging Spectrometry for Earth Remote Sensing , 1985, Science.

[31]  P. J. Camillo,et al.  A canopy reflectance model based on an analytical solution to the multiple scattering equation , 1987 .

[32]  A Goldman,et al.  The HITRAN database: 1986 edition. , 1987, Applied optics.

[33]  R. Dickinson,et al.  Albedos of homogeneous semi-infinite canopies: comparison of two- stream analytic and numerical solutions. , 1987 .

[34]  C. B. Farmer,et al.  Stratospheric trace gases in the spring 1986 Antarctic atmosphere , 1987, Nature.

[35]  L. Grant.  Diffuse and specular characteristics of leaf reflectance , 1987 .

[36]  J. H. Shaw,et al.  Measurements of odd nitrogen compounds in the stratosphere by the ATMOS experiment on Spacelab 3 , 1988 .

[37]  F. X. Kneizys,et al.  Users Guide to LOWTRAN 7 , 1988 .

[38]  J. Susskind,et al.  First-Guess Dependence of a Physically Based Set of Temperature Humidity Retrievals from HIRS2/MSU Data , 1988 .

[39]  C. Wessman,et al.  Remote sensing of canopy chemistry and nitrogen cycling in temperate forest ecosystems , 1988, Nature.

[40]  J. Kirk.  Solar heating of water bodies as influenced by their inherent optical properties , 1988 .

[41]  S. Macenka,et al.  Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) , 1988 .

[42]  Michel M. Verstraete,et al.  Radiation transfer in plant canopies: Scattering of solar radiation and canopy reflectance , 1988 .

[43]  A. Goetz,et al.  The high resolution imaging spectrometer (HIRIS) for Eos , 1989 .

[44]  V. Salomonson.  The Moderate Resolution Imaging Spectrometer (MODIS) , 1990 .