Derivation of scaled surface reflectances from AVIRIS data

Journal Article · · Remote Sensing of Environment; (United States)

OSTI ID:6339460

Goetz, A F.H. ^[1]; Gao, Bocai; Heidebrecht, K B

---

1. Univ. of Colorado, Boulder (United States)

Analysis of high resolution imaging spectrometer data requires a thorough compensation for atmospheric absorption and scattering. A method for retrieving scaled surface reflectances,' assuming horizontal surfaces having Lambertain reflectances, from spectral data collected by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)(Vane, 1987) is presented here. In this method, the integrated water vapor amount on a pixel by pixel basis is derived from the 0.94-[mu]m and 1.14-[mu]m water vapor absorption features. The transmission spectrum of water vapor (H[sub 2]O), carbon dioxide (CO[sub 2]), ozone (O[sub 3]), nitrous oxide (N[sub 2]O), carbon monoxide (CO), methane (CH[sub 4]), and oxygen (O[sub 2]) in the 0.4-2.5 [mu]m region is simulated based on the derived water vapor value, the solar and the observational geometry, and through use of narrow band spectral models. The scattering effect due to atmospheric molecules and aerosols is modeled with the 5S computer code (Tanre et al., 1986). The AVIRIS radiances are divided by solar irradiances above the atmosphere to obtain the apparent reflectances. The scaled surface reflectances are derived from the apparent reflectances using the simulated atmospheric gaseous transmittances and the simulated molecular and aerosol scattering data. The scaled surface reflectances differ from the real surface reflectances by a multiplicative factor. In order to convert the scaled surface reflectances into real surface reflectances, the slopes and aspects of the surfaces must be known. For simplicity, the scaled surface reflectance is simply referred to as the surface reflectance' in this article. The method described here is most applicable for deriving surface reflectances from AVIRIS data acquired on clear days with visibilities 20 km or greater. More rigorous atmospheric radiative transfer modeling is required in order to derive surface reflectances from AVIRIS data measured on hazy days.

• OSTI ID: 6339460
• Journal Information: Remote Sensing of Environment; (United States), Vol. 43:2-3; ISSN 0034-4257
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
29 ENERGY PLANNING
POLICY AND ECONOMY
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
CARBON MONOXIDE
METHANE
NITROUS OXIDE
OZONE
WATER VAPOR
AEROSOLS
REMOTE SENSING
SIMULATION
SPECTROMETERS
ALKANES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
COLLOIDS
DISPERSIONS
FLUIDS
GASES
HYDROCARBONS
MEASURING INSTRUMENTS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SOLS
VAPORS
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
290301 - Energy Planning & Policy- Environment
Health
& Safety- Regional & Global Environmental Aspects- (1992-)