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An estimate of the processes of afforestation and forest restoration after fires is relevant for a significant territory of Russia, including due to the issue of carbon neutrality. In this paper we examine the possibilities of radar monitoring of the afforestation process based on the Cloude–Pottier decomposition of dual-polarization L-band data time series. Preliminary segmentation is performed based on the minimal radar backscatter values for the entire observation period. This makes it possible to separate into a separate class treeless areas and open forests, both those that existed before the beginning of the study and those that formed later. Next, polarimetric decomposition is performed by the Cloude–Pottier method to obtain parameters H (entropy) and α (scattering angle) and form time series from them. Research showed the fundamental possibility of monitoring forest dynamics on the H-α plane, where the points of the test plots form characteristic time tracks. A mature dense forest, the characteristics of which are assumed to be constant, was used as a reference for estimating the rate of change on the H-α plane. [ABSTRACT FROM AUTHOR]

In this paper, the possibilities of remote sensing of moisture profiles in the arable layer were theoretically and experimentally studied based on the nadir measurements of reflection coefficients at three frequencies of 1.26 GHz, 796 MHz and 641 MHz. The reflection coefficients were measured by the impulse method during natural cycles of evaporation and moistening of an arable layer at the agricultural field being under steam, located at 56°05ʹN, 92°40ʹ E in the area of the Minino village, Krasnoyarsk region, the Russian Federation. The soil moisture profiles were retrieved in the course of solving the inverse problem, in which the reflection coefficients at different frequencies acted as an informative sign. The root-mean-square error and the determination coefficient (R2) between retrieved and measured moisture values in the topsoil thickness of 0.15 m were 3.3% and 0.79, respectively. In the course of theoretical calculations, it was shown that in practice, it is impossible to predict the sensing depth of the arable layer without preliminary information on the form of moisture profile. Moreover, the sensing depth depends not only on the form of soil moisture profile but also on frequency. In this regard, it is impossible to correlate the effective soil moisture, retrieved from single-frequency measurements of the reflection coefficient in the approximation of homogeneous topsoil, with the specific thickness of topsoil. The study shows the promise of developing multi-frequency radar systems for remote sensing of soil moisture profiles in the arable layer, the potential of which can be realized on lightweight unmanned area vehicle (UAV) platforms. [ABSTRACT FROM AUTHOR]

The article highlights Russia's influence operations in the Czech Republic during U.S.-Czech ballistic missile defense discussions and negotiations between 2002 and 2011. Russia's influence operations are an example of its first successful effort on a new North Atlantic Treaty Organization member state territory. They are significant because Russia will use similar approaches in other states and the United States must understand them before it can successfully counter them. This is a first public comprehensive effort to map them in connection to U.S.-Czech radar negotiations and draw conclusions for U.S. and allied foreign and defense policies. [ABSTRACT FROM AUTHOR]

Discusses U.S. congressmen's findings concerning their inspection of a radar in Krasnoyarsk, Russia. U.S. legislation mandating strict compliance with the Anti-Ballistic Missile (ABM) Treaty; Claims that the radar was constructed for ABM battle management; Congressmen's findings that the radar do not violate the ABM treaty.

Abstract: Interferometric synthetic aperture radar (InSAR) images reveal a pre-eruption deformation signal at Kizimen volcano, Kamchatka, Russia, where an ongoing eruption began in mid-November, 2010. The previous eruption of this basaltic andesite-to-dacite stratovolcano occurred in 1927–1928. InSAR images from both ascending and descending orbital passes of Envisat and ALOS PALSAR satellites show as much as 6cm of line-of-sight shortening from September 2008 to September 2010 in a broad area centered at Kizimen. About 20cm of opening of a nearly vertical dike provides an adequate fit to the surface deformation pattern. The model dike is approximately 14km long, 10km high, centered 13km beneath Kizimen, and strikes NE–SW. Time-series analysis of multi-temporal interferograms indicates that (1) intrusion started sometime between late 2008 and July 2009, (2) continued at a nearly constant rate, and (3) resulted in a volume expansion of 3.2×107 m3 by September 2010, i.e., about two months before the onset of the 2010 eruption. Earthquakes located above the tip of the dike accompanied the intrusion. Eventually, magma pressure in the dike exceeded the confining strength of the host rock, triggering the 2010 eruption. Our results provide insight into the intrusion process that preceded an explosive eruption at a Pacific Rim stratovolcano following nearly a century of quiescence, and therefore have implications for monitoring and hazards assessment at similar volcanoes elsewhere. [Copyright &y& Elsevier]

A preliminary stage in developing comprehensive conservation plans involves identifying areas used by the organisms of interest. The areas used by migratory land birds during temporal breaks in migration (stopover periods) have received relatively little research and conservation attention. Methodologies for identifying stopover sites across large geographic areas have been, until recently, unavailable. Advances in weather-radar technology now allow for evaluation of bird migration patterns at large spatial scales. We analyzed radar data (WSR-88D) recorded during spring migration in 2000 and 2001 at 6 sites in the Great Lakes basin (U.S.A.). Our goal was to link areas of high migrant activity with the land-cover types and landscape contexts corresponding to those areas. To characterize the landscapes surrounding stopover locations, we integrated radar and land-cover data within a geographic information system. We compared landscape metrics within 5 km of areas that consistently hosted large numbers of migrants with landscapes surrounding randomly selected areas that were used by relatively few birds during migration. Concentration areas were characterized by 1.2 times more forest cover and 9.3 times more water cover than areas with little migrant activity. We detected a strong negative relationship between activity of migratory birds and agricultural land uses. Examination of individual migration events confirmed the importance of fragments of forested habitat in highly altered landscapes and highlighted large concentrations of birds departing from near-shore terrestrial areas in the Great Lakes basin. We conclude that conservation efforts can be more effectively targeted through intensive analysis of radar imagery. [ABSTRACT FROM AUTHOR]

A comparison of thundercloud characteristics in different regions of the world was conducted. The clouds studied developed in India, China and in two regions of Russia. Several field projects were discussed. Cloud characteristics were measured by weather radars, the SEVERI instrument installed on board of the Meteosat satellite, and lightning detection systems. The statistical characteristics of the clouds were tabulated from radar scans and correlated with lightning observations. Thunderclouds in India differ significantly from those observed in other regions. The relationships among lightning strike frequency, supercooled cloud volume, and precipitation intensity were analyzed. In most cases, high correlation was observed between lightning strike frequency and supercooled volume. [ABSTRACT FROM AUTHOR]

Offset fields between pairs of JERS-1 satellite SAR data acquired in winter with 44 days time interval were employed for the estimation of Arctic glacier motion over Svalbard, Novaya Zemlya and Franz-Josef Land. The displacement maps show that the ice caps are divided into a number of clearly defined fast-flowing units with displacement larger than about 6 m in 44 days (i.e. 50 m/year). The estimated error of the JERS-1 offset tracking derived displacement is on the order of 20 m/year. Occasionally, azimuth streaks related to auroral zone ionospheric disturbances were detected and dedicated processing steps were applied to minimize their influence on the estimated motion pattern. Our analysis demonstrated that offset tracking of L-band SAR images is a robust and direct estimation technique of glacier motion. The method is particularly useful when differential SAR interferometry is limited by loss of coherence, i.e. for rapid and incoherent flow and large acquisition time intervals between the two SAR images. The JERS-1 results, obtained using SAR data acquired by a satellite operated until 1998, raise expectations of L-band SAR data from the ALOS satellite launched in early 2006. [Copyright &y& Elsevier]

Abstract: This paper presents the results of analyzing the experimental data from the Irkutsk incoherent scatter radar, GPS receiver in Yakutsk, digital ionosounders for vertical- and oblique-incidence sounding combined with auroral images during geomagnetic disturbances as a consequence of high flaring activity of the Sun from 19 to 29 of October, 2003. Overall the observations can be interpreted in terms of the thermosphere storm model and main ionospheric trough motion. At once the negative critical frequency disturbance observed during the major storm on October 29 can not be explained in terms of the noted models. [Copyright &y& Elsevier]