EXPERIMENTAL RESEARCH OF RADIO THERMAL contrasts of the OBJECT IN THE MILLIMETer wavelength range

 

L. I. Fedoseev, R. P. Bystrov, À. D. Êràsnjnsky, I. V. Kuznetsov, J. V. Lebsky, V. A. Maltsev, A. A. Shvetsov, A. P. Shkaev, A. M. Shtanjuk

 

Applied Physics Institute of RAS, Nizhniy Novgorod

Received December 13, 2010
 

Abstract. The summary results the hardware-methodical workings out and measurements radio-thermal contrasts of district and objects on its background in a millimeter range of lengths of waves are given. Questions of formation, ordering and forecasting of radio thermal contrasts are mentioned.

The supervision begun still in 40th years own ÑÂ× radiations of atmosphere of the Earth have been spent for the first time in 1946 by Daik. Detailed researches of selective radiations of atmospheric components are executed by V.S.Troitskiy, S.A.Zhevakin. In 50th years successful development of a range of millimeter waves were continued, and soon it has led to creation of unique sources of radiation - backward-wave tube, high-sensitivity not cooled radio astronomical reception equipment, high-precision mirrors etc. on waves up to 1 mm. Later works by electrodynamics and statistical calculations of spectral and spatial characteristics of radio thermal radiation of gaseous environments and the environments, which are limited  by smooth surfaces. Representations about mechanisms of fluctuation of intensity radio-thermal radiations are developed. Measurement techniques for millimeter wave radiation is developed taking into account the requirements of scientific and applied researches. Use of all of it has allowed to receive an extensive data set on atmospheric  absorption and radiation. There was naturally a question about the application of all listed above in applied researches, radio thermal in particular. The first works in this area were directed to the data acquisition for the estimation of degree of a marketability of possible applications of radio thermal systems in the conditions of unusually big absorption (from the points of view of that time). The following works have been directed on revealing the relation between the main radiometric characteristics of the object:  it's brightness contrast with the background and atmosphere characteristics, strongly depending in millimeter wave range upon meteorological  conditions, a season and a relief. The establishment of such relation would allow to solve a problem of forecasting of contrasts in various regions with various environmental conditions, and then of a maximum efficiency in them of any radio-thermal systems, having optimized thus their working frequencies and other parameters. Importance of such approach to researches is not lost now. Results of hardware-methodical workings out and the natural researches executed by group of employees in Applied Physics Institute of the Russian Academy of Sciences.

 

Keywords: radio thermal contrast, millimeter waves, own radiation, receiving equipment, fluctuation, atmosphere, radio thermal background, radiometer.