Search

Measurements were made with use of microwave radiometer-spectrometer P22M working in the range of 18–27.2 GHz with a spectral resolution of 200 MHz. Experimental results were compared with model calculations. Along with general correspondents of experimental and model results, there are some mismatches in the details. Variability of spectral characteristics of radiation is analyzed on a series of measurements obtained under different weather conditions: clear sky, clouds and the initial stage of precipitation. Such measurement may be useful for development of new techniques in vertical atmospheric profiles retrieval.

Performance of 142-and 204-GHz radio spectrometers is optimized for remote sensing of ozone and chlorine monoxide in the Earth’s atmosphere by means of computer simulation. Versions of spectrometers with one broadband acousto-optical and two filtering spectrum analyzers optimized in frequency resolution are considered. A brief description of the spectrometers and their basic units is given.

We describe the design of a waveguide planar Schottky-diode mixer for frequencies of about 200 GHz and a measurement system for testing the mixer performance. A backward-wave oscillator with a frequency doubler was used as the local oscillator. The results of room-temperature measurements of the mixer conversion losses and noise temperature as functions of the frequency and power of the local oscillator are presented.

Designs and basic characteristics are considered for imagers having ellipsoidal-mirror and lens antennas. These operate in the 8 mm range and are intended for ultrasensitive measurement of millimeter-range field patterns and for the construction of images by computer processing.

The Russian Academy of Sciences and Federal Space Agency, together with the participation of many international organizations, worked toward the launch of the RadioAstron orbiting space observatory with its onboard 10-m reflector radio telescope from the Baikonur cosmodrome on July 18, 2011. Together with some of the largest ground-based radio telescopes and a set of stations for tracking, collecting, and reducing the data obtained, this space radio telescope forms a multi-antenna ground-space radio interferometer with extremely long baselines, making it possible for the first time to study various objects in the Universe with angular resolutions a million times better than is possible with the human eye. The project is targeted at systematic studies of compact radio-emitting sources and their dynamics. Objects to be studied include supermassive black holes, accretion disks, and relativistic jets in active galactic nuclei, stellar-mass black holes, neutron stars and hypothetical quark stars, regions of formation of stars and planetary systems in our and other galaxies, interplanetary and interstellar plasma, and the gravitational field of the Earth. The results of ground-based and inflight tests of the space radio telescope carried out in both autonomous and ground-space interferometric regimes are reported. The derived characteristics are in agreement with the main requirements of the project. The astrophysical science program has begun., 54 pages, 11 figures; published by Astronomicheskij Zhurnal (in Russian) and Astronomy Reports (in English)

The results of development and investigations of ultra-low-noise waveguide and quasioptical receivers of millimeter wave band region based on SIS mixers are presented. The possible cryogenic components of millimeter wave band receivers based on SIS junctions such as dc SQUID IF amplifiers, SIS noise sources, cooled ferrite phase-shifters-modulators, superconducting mm-wave local oscillators, superconducting analog-to-digital converters were designed, produced and experimentally studied. The prospects of creation the entirely superconducting integrated receiving circuits containing all mentioned above superconducting components are discussed.