Atmospheric attenuation and scattering determined from multiheight multispectral scanner imagery

Multispectral tests were conducted near Peterborough, Cambridgeshire, UK on Sept. 18, 1982. Data consisted of six 11-channel images from six altitudes ranging from 500 to 3000 m. The data available consisted of meteorological and radiation data and of ground spectral reflectivity. The temperature and dew point profiles indicated a stable atmosphere to 3000 m and above. On a sequence of overpasses from the highest altitude to the lowest, a decrease in solar irradiance was observed. At each altitude, digital readings were averaged over selected ground locations. Changes in altitude allowed the elimination of scattering by determining differences between areas and attenuation. The test results indicate that certain layers of the atmosphere may have unusually high attenuation and scattering and that at higher altitudes upward-scattered radiation can be several times more intense than the surface signal.