P. P. Fedchenko

Remote sensing of the state of crops and soils

Abstract Various techniques as well as some general problems of agricultural remote sensing are discussed, with emphasis on the development of techniques to assess soil productivity (humus content) and the slate of crops (weediness, etc.). The techniques considered were tested in conditions of the southern part of the USSR European territory (the Ukraine, Moldavia). Applications of the technique have been exemplified.

The use of reflection spectra in recognition of crops

Abstract The use of reflection spectra to recognize crops has been discussed. A technique to exclude the contribution to SBC by soil and weeds has been suggested.

METHODOLOGICAL ISSUES IN ASSESSMENT OF THE CONDITION OF AGRICULTURAL CROPS BY REMOTE SENSING

A new method is proposed for determining the spectral brightness coefficients (SBC) of agricultural crops, making it possible to exclude contributions to the formation of the brightness field caused by bare soil and weedy vegetation. This makes possible a substantial increase in the accuracy in determining actual biomass of agricultural crops. It is shown that the use of measurement data not only for brightness, but also for the polarization of radiation ascending from the sensed object, ensures a quite reliable assessment of the share of damaged agricultural crops.

THE STUDY OF CHANGES IN SOIL QUALITY BY REMOTE SENSING METHODS

A general review article presents the results of Soviet and world developments in monitoring and mapping soil erosion and changes in soil physical and chemical properties by remote sensing methods. More specifically, methods are described for determining contents of humus, moisture, and iron oxide, and properties of ion exchange from spectral brightness curves; and for mapping of areas of wind and water erosion from remote sensing imagery. Diagrams showing autocorrelational and cross-correlational relationships among soil spectral brightness values recorded in 1973 and 1981, reflecting changes in humus content in 3 types of soils as a result of prolonged cultivation, are included. Translated from: Geografiya i prirodnyye resursy, 1985, No. 3, pp. 101-109.

Studies of vegetation and soils from aerospace measurements

Abstract The problem of soil and vegetation recognition with the use of satellite-derived digitized images and sub-satellite spectral brightness measurements at test sites data is discussed. A technique for retrieval of soil humus content is suggested.

An experience gained from the use of reflection spectra for determination of the humus content in soils

Abstract It has been shown that colour coordinates are the most representative characteristic from which the content of humus in soils can be quantitatively estimated. The results have been presented of determination of the humus content in soils from spectral measurements made in laboratory and field conditions.