Data of remote multiangle measurements of reflected radiance are used for retrieval of the optical thickness, single
scattering albedo and phase function parameter of cloudy and clear atmosphere. The method of perceptron neural
network has been tried for obtaining the surface albedo, optical thickness, single scattering albedo and phase function
parameter from input values of multi-angle radiance and solar incident angle of clear pixels. All mentioned
parameters were randomly varied on the base of statistical models of possible measured parameters variation. An
analytical method of the retrieval is applied to remote observations of reflected radiance of cloudy pixels. The slight
horizontal heterogeneity of cloud is approximately taken into account. The simultaneous retrieval of the optical
thickness and single scattering albedo at every wavelength independently and without rough restrictions on
parameters retrieved is the advantage comparing with earlier studies. The methodology of the asymmetry parameter
retrieval is proposed.
Optical parameters of clouds retrieved from numerous spectral radiation observation of different kinds revealed a dramatic conflict with results simulated with the scattering Mie theory. Namely, true absorption appears greater than it follows from Mie theory and the scattering coefficient together with the optical thickness exhibit clear spectral dependence. Obtained values of the optical parameters easily explain the "anomalous absorption" within clouds heatedly discussed last decade.
The present state of the environment and natural resources of our planet, their ecodynamics and development tendencies demand special attention to determination of environmental parameters which will serve as indicators of ecological stability and safety. The methods of atmospheric optics instrumentation are proposed here for solution of indicated problem.
In 80-th vast airborne experiments were performed by Atmospheric Physics Department of Physical Institute of St. Petersburg University in different geographical regions and above various underlying surfaces. Statistics and analysis of these numerous data allowed to obtain the criteria of making out of various water and ground surfaces and to carry out their classifications. By making use the criteria elaborated, there were revealed by 14 classes for water and ground surfaces (total 28 classes).
The strict analytical formulas are derived from asymptotic formulas of the radiative transfer theory for determination of optical thickness and single scattering albedo on base of measurements reflected or transmitted solar radiance or irradiance in strati clouds. The detailed error analysis of the methodology proposed is carried out. The formulas obtained are applied for interpretation of the spectral data of ground- based measurements at the drifting Arctic station in 1979. The values of optical thickness and single scattering albedo are obtained and reveal the apparent spectral dependency.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.