Oleg I. Smokty

Remote Sensing of the Earth from Space: Atmospheric Correction

The practical use of space-borne information, its processing and interpretation needs atmospheric correction of aerospace images and spectra. With this book the authors offer a review of this young technique and present their results from 20 years work. The atmospheric modulation transfer function is elucidated from the first theoretical investigations to practical aspects of the atmospheric correction of space imagery. The problems are analysed by modelling the main important parameters, e.g. the atmospheric aerosol, radiative transfer in the Earths surface - atmosphere systems, interaction of short - and longways components of the radiation budget with the atmosphere and the Earths surface.

Multiple light scattering in the spherical planetary atmosphere

In recent years in view of the intensive development of the investigations of near the ground space and planetary atmospheres with satellites and space rockets we can observe an increased interest as to the development of techniques for the solution of the problems on the radiative transfer theory in which the curvature of atmospheric layers is to be allowed for. Until very recently in solution of most of the problems on transfer theory the real geometry of a planetary atmosphere was not taken into account. Planetary atmospheres were supposed to consist of planeparallel layers illuminated, along their extension, by parallel solar rays [1] z), [2]. Such suggestions markedly simplify the consideration of the process of multiple light scattering in the planetary atmosphere. They can be fully justified only in the cases when the sun is located high above the horizon and the direction of sight is not near that to the horizon. At present a large number of various investigations and calculations has been carried out using a plane model of the planetary atmosphere illuminated by parallel solar rays. In particular, the most complete calculations for the optical state of a plane planetary atmosphere have been conducted for the case of the earths atmosphere. (see [3]-[6]). However, there is a number of problems interesting and important for practical purposes the correct solution of which is impossible without the consideration of a real geometry of the planetary atmosphere. These involve the following: the calculation of planetary atmospheric brightness near the terminator and the horizon [7], building of a strict theory of twilight phenomena in the terrestrial and planetary atmospheres [8]-[10], calculation of L~ quantum diffusion in the upper atmosphere of the Earth [11], some problems on space satellite and manned spacecraft navigation etc. Systematic consideration of the transfer theory problems has recently been started in the works by V. V. SOBOLEV and I. N. MIN~N [12]-[16]. The present paper reports the results of further investigations and calculations [20]-[22] made basing on references [13]-[15] and using the approximated geometrical model for a planetary atmosphere [161.

Visual Observations and Spectral Investigations of the Earth's Atmosphere Twilight Aureole from the Soyuz-5 Spacecraft.

Results are given of the spectrophotometric measurements of the earths atmosphere twilight aureole as first performed from the Soyuz-5 spacecraft. The analysis is made of the experimental findings depending on the wavelength, the perigee height of the sight ray above the earths surface, the sunset angle, etc.. The comparison is carried out of the vertical profiles for the twilight aureole monochromatic brightness with the results of the corresponding theoretical calculations for the aerosol Elterman model (1968). The color diagram and pictures of the twilight aureole are built using theoretical values of the brightness aureole for different terrestrial atmospheric models and employing the experimental data and the results of visual observations from the Soyuz-5 spacecraft.

Geophysical investigations on manned spacecrafts

SummaryReview has been made of the first results and perspectives of investigations in geophysics and bordering sciences (geology, geography, agrobiology, etc.) by means of manned orbital space laboratories. Relatively detailed discussion is given to the problems of the interpretation of terrain feature pictures from space. Attentively considered are the technique and results of the photometric processing of atmospheric photographs near the horizon with the purpose of studying atmospheric optical non-homogeneities (in particular, aerosol layers). The possible investigations based on the use of data about the outgoing radiation spectra are mentioned.РезюмеСделан обзор первых резулътатов и перспектив исследований в области геофизики и смежных наук (геология, георафия, агробиология и др.) при помощи пилотируемых орбиталъных космических лабораторий. Сравнительно детальо обсуждены проблемы интерпретации фотографий земных образований из космоса. Родробно рассмотрены методика и результаты фотометрической обработкн фотографий атмосферы вблизи горизонта с целью изучения оптических неоднороднотей (в частности, аэрозольных слоёв) в атмосфере. Упомянуты возможности исследований на основе использования данных о спектрах уходящего излучения.

A One-Dimensional Scalar Transfer Function of the Atmosphere

To reduce the spectrophotometric information obtained from the Earth’s survey from space, a theoretical determination of the transfer function for the brightness of the atmosphere-object-background system is important [31, 94, 273, 288]. Using the spatial inhomogeneity of spectrophotometered surfaces (backgrounds), parts of which are “cut out” by the space-born spectrophotometer’s slit during the survey from a space-borne platform, the system “object-background” can be divided conditionally into the following types (Fig. 4.1): (1) a horizontally homogeneous, infinitely extended surface (background); (2) a small (point) object against a horizontally-homogeneous, infinitely-extended background; (3) a set of randomly distributed small (point) objects against an extended background; (4) an interface between two horizontally homogeneous surfaces.

The Radiation-Environment Interaction

The practical use of the results of the Earth studies from space is largely determined by the possibility of solving two basic problems: developing automated systems to process and interpret video information (ASPIV) and establishing relationships between the parameters characterizing the environmental state and the outgoing radiation field. The development of special processors, the networking and use of computers in series, and the development of computer-processing mathematical-support help in solving the first problem. The solution of the second problem is connected with mathematical description of the environment and of its interaction with electromagnetic radiation.

Optical-Physical Models of Atmospheric Aerosol

The optical parameters of a cloud-free atmosphere as a scattering medium are, firstly, determined by the presence of an aerosol, by its stratification, size distribution, chemical composition and other characteristics. The contribution of an aerosol to the absorption of radiation by the atmosphere in the optical wavelength region 0.2 -13 µm is also considerable. Besides, at certain sun elevations aerosols affect radiation absorption by the surface. Aerosols are generally understood to be the finest suspended particles, referring to all liquid and solid particles in the troposphere, stratosphere and at higher altitudes, but not cloud particles and ice crystals. An analysis performed recently both in the USSR and in other countries [9, 24, 59, 60, 65, 91, 92, 99, 104, 112, 153, 154, 231, 269] reveals the importance of aerosol radiative effects. However, there is no theory on the formation of the global aerosol field yet which determines the complex problem of the parameterization of its effect on the radiation fields in the atmosphere-surface system.

Radiative Correction of the Space-Derived Images of the Earth Surface

Techniques for the transformation of air- and space-derived images based on the mathematical apparatus of statistical solutions are now widely used. On the one hand, these transformations are aimed at the removal of distortions from space-derived information about the state of natural objects, and on the other hand, they improve the quality of the multispectral survey from both aircraft and satellites. Very often, however, transformations of images brightnesses are based on pure mathematical formalism, which does not consider the principal laws of formation of the outgoing radiation field. Transformations based on preliminary modeling of the processes of interaction of electromagnetic emission with the atmosphere and Earth’s surface are a qualitatively different way of removing atmospheric radiative distortions [347]. Here, the principal energy balance relationships and the related functions of conversion of radiation into the data recorded remotely by sensors are included. This approach to the transformation of spectral brightnesses obtained from multispectral air- and space-based survey will be used next.

Observations of the Earth Radiation Budget from Space

In this chapter we consider the western experience in the application of spaceborne hydrometeorological systems to assess the components of radiation budget at the Earth’s surface level.

Theoretical Models of the Non-Polarized Optical Radiation in the Atmosphere-Surface System

In studies of the Earth from space, the spectrophotometry of natural formations, surface and above-water objects on the day-side of the Earth, seen from MS and POS, are of great interest [1, 25, 141, 143, 191].