Atmospheric Corrections for In-Flight Satellite Radiometric Calibration
Abstract
Accurate determination of atmospheric effects is crucial to earth- based in-flight radiometric calibration of existing satellite systems. Such calibration work relies on computer codes which compute atmospheric transmittance due to both scattering and absorption processes. Two programs evaluated in this paper are 5S, the Simulation of the Satellite Signal in the Solar Spectrum, and LOWTRAN 6. Two solar radiometers of differing designs were used for atmospheric data collection. The collected data were used to compute total optical depths. Results obtained from the two instruments in the visible are compared. Modifications made to the autotracking instrument are discussed. The accuracy of existing methods for determining the amounts of key constituents actually present in the atmosphere at satellite overpass time is examined. The computation of integrated water vapor content based on solar radiometer data is discussed. Calculations to account for the effects of gaseous absorption in the near infrared spectral bands of a solar radiometer are outlined. Such corrections will facilitate calibration of these spectral bands. In conclusion, the effects on radiance at the satellite level of the uncertainties in the current determination of crucial atmospheric parameters such as the extent of gaseous absorption and the aerosol characterization are examined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA196124
Entities
People
- Richard J. Bartell
Organizations
- Air Force Institute of Technology