Figure 9 shows the inverted reflectance spectra for the polo field in comparison with a reflectance spectrum
measured at the polo field The agreement provides preliminary validation tliat the effects of the solar
irradiance spectrum, the aerosol scattering, the well mixed gas absorption and scattering, the water vapor
absorption have been compensated. Figure 10 shows the inverted apparent reflectance spectrum for the golf
course showing the expected vegetation absorption and cellular scattering spectrum.
Figure 10 : An AVIRIS inverted reflectance spectrum for the golf course
6 - CONCLUSION
Radiative transfer code based NLLSSF algorithms are described that allow direct estimation of parameters
constraining the absorption and scattering characteristics of the atmosphere. These parameters arc derived
directly from the imaging spectrometer measured spectral upwelling radiance. These NLLSSF algorithms were
applied to each spatial element of the AVIRIS data acquired over Jasper Ridge, California, in 1992. The
derived atmospheric parameters and illumination geometry were used to constraint the MODTRAN radiative
transfer code to invert the AVIRIS measured spectral radiance to apparent surface reflectance for each spatial
element A preliminary validation is given through comparison of the inverted apparent reflectance and the in
situ measured reflectance for a target in the data set. In inversion of imaging spectrometer radiance to apparent
surface reflectance. Surface reflectance is used to investigate molecular absorption and particle scattering
characteristics of constituents in the disciplines of ecology, geology, oceanography and snow hydrology.
Acknowledgments
This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under
contract with the National Aeronautics and Space Administration.