Modis Land Surface Reflectance Science Computing Facility

VALIDATION STATUS

The operational procedure for atmospheric correction over land reflectances can be approached as the case of an infinite Lambertian target, however the accuracy of an atmospheric correction process is highly variable with respect to the geometrical conditions, the aerosol loading and the spectral band considered. Figures 8.2(a) to 8.2(c), describe the surface reflectances for three sites under different atmospheric and geometrical conditions, and the simulated top of the atmosphere signal using the 6S radiative transfer code for each of the seven MODIS land bands. Following information can be reached at: Operational Atmospheric Correction of MODIS Visible to Middle Land Surface Data in the case of an Infinite Lambertian Target

It is necessary to examine the impact of the atmospheric effect on the MODIS land bands reflectances, estimating the accuracy of the atmospheric correction and the impact of the sources of uncertainties under several scenarios and with defined parameters as those illustrated below:

BOOK

In that way we ran a set of simulations which are described in the following tables and charts (restricted only to Belterra site), to illustrate the uncertainties derived from:	_Calibration Uncertainties
	_Uncertainties on Ancillary Data Pressure
	_Uncertainties on Ancillary Ozone Amount
	_Uncertainties on the Water Vapor Amount
	_Uncertainties on the Aerosol Model
	_Overall Uncertainties

_Calibration Uncertainties

_Uncertainties on Ancillary Data Pressure go upX




















_Uncertainties on Ancillary Ozone Amount go upX

















_Uncertainties on the Water Vapor Amount go upX













_Uncertainties on the Aerosol Model (Smoke low absorption) (Urban polluted) (Smoke high absorption) go upX























_Overall Uncertainties go upX This assessment confirms the validity of the theoretical error budget presented here but need to be extended to cover more conditions. For full text research please go to: Operational Atmospheric Correction of MODIS Visible to Middle Land Surface Data in the case of an Infinite Lambertian Target.

Principal Investigator: Dr. Eric F. Vermote University of Maryland Department of Geography and NASA GSFC code 614.5	Correspondence to: 4321 Hartwick Rd. Suite 209 College Park, USA E-mail: mod09@ltdri.org
Responsible NASA Official: Ed Masouka	Web site design: mod09@ltdri.org
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