This invention discloses several improved methods of correcting for
atmospheric effects on a remote image of the Earth's surface taken from
above, wherein the image comprises a number of simultaneously acquired
images of the same scene, each including a large number of pixels, each
at a different wavelength band, and including infrared through
ultraviolet wavelengths. One method is for retrieving the aerosol/haze
amount (i.e., visible range) from an assumed ratio of in-band
reflectances, rather than from an assumed reflectance value. Another
method is for identifying cloud-containing pixels. This is used to
improve the calculation of the spatially averaged radiance L*.sub.e and
reflectance .rho..sub.e images in standard equations. Another method
greatly reduces the number of mathematical operations required to
generate the reflectance values. This method operates by averaging the
water vapor and .rho..sub.e values over small groups of neighboring
pixels, so that the same A, B, S, L*.sub.a parameter values may also be
assigned to all pixels within the group. Yet another new method accounts
for shifts in the wavelength calibration within the image, such as would
be caused by spectral "smile". This method loops the calculation of A, B,
S and L*.sub.a over a set of possible wavelength shifts with respect to
the input channel centers, and assigns the appropriate set of parameters
to each pixel based on a pixel-location-dependent formula for the
wavelength shift.