Determination of troposphere characteristics using signals of satellite navigation systems

Based on two-frequency phase measurements of GNSS signals by ground-based receivers, zenith delays of radio signals in the troposphere are estimated. These estimates are compared with the NCEP/NCAR reanalysis data on weather fields. It is shown that the standard deviation in the values of zenith delays obtained in both ways is about 1 cm on average. According to our calculations, such a level of accuracy permits one to study the interday and intraday dynamics of the troposphere. The temporal resolution of estimates based on the GNSS data is 2 h, which makes it possible to organize atmosphere monitoring using a ground-based network of satellite tracking systems. © 2012 Pleiades Publishing, Ltd

Nanoindentation and Strain Characteristics of Nanostructured Boride/Nitride Films

The hardness, elastic modulus, and elastic recovery of nanostructured boride/nitride films 1–2 µm thick have been investigated by the nanoindentation technique under the maximum loads over a wide range (from 5 to 100 mN). It is demonstrated that only the hardness parameters remain constant at small loads (5–30 mN). The data obtained are discussed and compared with the parameters determined by other methods

Influence nonuniformity of the atmospheric water vapor field on the phase measurements of radio signals from global navigation satellite systems

We present the experimental results for the horizontal gradients of integrated content of atmospheric water vapor, which are retrieved from the phase measurements of signals in the receiver network of the global navigation satellite systems in 2011 in the Republic of Tatarstan. The seasonal gradient variation is found. The meridional gradient usually shows a decrease in integrated water vapor with increasing latitude, and its monthly mean values are equal to -1.8 mm and 0.1 mm of precipitable water per 100 km in August and December, respectively. The zonal monthly average gradient is somewhat smaller in magnitude than the meridional one and is equal 0.1 mm and -0.8 mm per 100 km in March/June and May/October, respectively. Instantaneous values of the gradients can by an order of magnitude higher than the monthly mean values. Contribution from the gradient of integral water vapor to the phase-measurement difference between two antennas spaced 30 km apart is shown to attain its maximum of 141.5 mm in August for the zenith angle 80. Errors in determining the mutual location of the ground-based antennas of global navigation satellite systems due to the water vapor gradients can reach 66 mm and 16.9 mm in August and February, respectively. © 2013 Springer Science+Business Media New York

Variability of GPS-derived zenith tropospheric delay and some result of its assimilation into numeric atmosphere model

The total zenith tropospheric delay (ZTD) is an important parameter of the atmo- sphere and directly or indirectly reflects the weather processes and variations. This paper presents a hardware and software complex for continuous measurements and prediction of atmospheric thermodynamics and radiowaves refraction index. The main part is a network of ground-based spatially separated GPS-GLONASS receivers, which allows the remote sensing zenith tropo- spheric delay. GPS-Derived Zenith Tropospheric Delay shows the day to day variation and mesoscale spatial and temporal variability. Comparison with the numerical weather reanalysis fields and solar photometer measurements showed agreement with the relative deviation of less than 10%. Hardware-software complex includes the numerical model of the atmosphere on a computational cluster. A variational assimilation system was used to examine the comparative impact of including satellite derived total zenith tropospheric delay from GPS and GLONASS ground observations. Preliminary results show that the initial field of radiowaves refraction index was improved by assimilating the satellite derived ZTD

Recoil Studies in the Reaction of 12-C Ions with the Enriched Isotope 118-Sn

The recoil properties of the product nuclei from the interaction of 2.2 GeV/nucleon 12-C ions from Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna with a 118-Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The results for 12-C ions are compared with those for deuterons and protons. Three different Los Alamos versions of the Quark-Gluon String Model (LAQGSM) were used for comparison with our experimental data.Comment: 10 pages, 6 figures, submitted to Nucl. Phys.