Vol 14, No 5 (2013)

The actual state and perspectives of the Russian space radar constellation, its ground segment facilities and remote sensing data integrated processing technologies are presented.

In the work the authors present the results of validation of algorithms of restoration of snow water equivalent for steppe regions of Western Siberia. Microwave data from AMSU-A and AMSR-E radiometers installed on the satellite NOAA and Aqua platforms were a source of basic data. It is shown that for two-frequency algorithms, the correlation coefficient between the real and restored values of moisture content changes from 0,06 to 0,5 at average value 0,3. The statistical importance of the received estimates is insignificant and corresponds to a case of strong spatial averaging (about 50 km in pixel) that also reduces a value of results. It is shown that almost applicable accuracy (it is better 40 %) is reached at considerable averaging - more than 40 points. It corresponds to temporary averaging to level of average monthly indicators or to spatial averaging on an element of 280x280 sq. km.

Results of the analysis of brightness characteristics of soil during freezing/thawing process and frozen state are presented. It is found that the brightness temperature measured by MIRAS radiometer of the SMOS-satellite, changes only slightly during the soil freezing due to the climatic and geographical features of the south of Western Siberia. It is shown that satellite data like ground measurements poorly correlate with the parameters characterizing the state of the soil while it is in the frozen state. The effect of azimuth survey regarding from the meridional direction at the time evolution of brightness temperature during snow thawing was observed. Founded dependences should be taken into an account in the processing and use of the SMOS satellite radiometric data.

The results of brightness temperature investigation in Buryatia made with microwave radiometer SMOS/MIRAS are presented. As an example, the points located on water area of Lake Baikal and near the lake are considered. The results obtained in the summer and winter period are presented as well. It is shown that there is a significant discrepancy between theory and experiment for a point on the water area of Lake Baikal, a satisfactory agreement for the point on the ground and a good agreement for the control point located in the equatorial waters. It is concluded that the results obtained with the radiometer are reliable.

The presented calibration polygon complex (CPC) is intended for verification and validation of radar images (RI). Results of the flight experiment: imaging of CPC “Skripali ” (Ukraine) by the S/C “Radarsat-2” and the subsequent analysis of the gained images have led to the conclusion about basic readiness CPC for acknowledging of RI performances from S/C “Kondor-E” at a stage of flight tests and verification and validation RIfrom other systems.

Multifrequency airborne SAR “Compact” was designed to operate in X,L P and VHF band, mounted on board of Mi-8 helicopter without the need of any platform modification. The comparative analysis of backscattering properties for some natural surfaces was performed with the use of generated SAR images. Backscatter coefficients for surfaces for different bands were calculated. The examples of 4-band SAR observations are demonstrated. The joint use of multifrequency radar data seems to be an interesting instrument in SAR image analysis of natural surfaces and water areas.

The textural segmentation of lake Baikal ice cover have been done by means of GLCM, using ALOS PALSAR one channel images in freezing period of 2010 year. The textural features and surface fractal dimension have been calculated in 140 points along the crack T1 for January and March, and texture change connection with temporal and spatial ice deformation dynamics is hypothecated.

The results of the interferometric processing of multi-time data of radar PALSAR are presented. Monitoring of subsidence of the earth surface with subsidence mould formation was performed on the oil and gas fields in Western Siberia. The advantages of PSI method implementation in MatLab package on a high supercomputing cluster are considered.

Techniques of multitemporal coherent radar composites generation is considered in the article. Keys for colors interpretation on such composites are described. Examples of SAR and combined SAR-optical composites usage for thematic mapping and clear-cuts mapping in forestry are presented.

The results of ASAR/ENVISAT data DInSAR processing for earthquake in Japan by means of SARscape software are presented. Results of the joint analysis of SAR data and ground-based GPS precision measurements are presented.

Currently at the northern territory of Russia large-scale destructive processes take place, as a result of increase of anthropogenic pressure and climate change. Based on radar images of Yamal peninsula and Yamal-Nenetsk Autonomous Area, the areas of microstrain and landslides were localized by means of differential interferometry and texture analysis technique.

On the basis of two test forestry of Republic of Buryatia it was developed a technique combining high-resolution multispectral and radar data for forests mapping.

The results of studies of deformation and dynamics of the ice cover of Lake Baikal on the basis of radar data and ground-based GPS-measurements. Speckle interferometry method determined the values and directions of the horizontal displacements of ice massifs in the southern basin and around peninsula Svyatoi, which are in good agreement with ground-based GPS-measurements.

This article presents the results of work on the creation of the data bank of basic products on SAR-data in Research Center for Earth Operative Monitoring of JSC “Russian Space Systems". The article contains examples of products with technological cycle of production implemented in 2012, and plans for the further development of technologies.

The measurements of the complex dielectric constant (CDC) of soils with low water content at the frequencies 1 MHz — 4 GHz are performed. It is shown that the CDC of bound water at frequencies below 1—1.5 GHz depends on it’s quantity in the soil. A model of the frequency and moisture dependence, including three frequency areas of relaxation, is created. It is shown that account of the dependence of CDC of bound water on its quantity can significantly improve the accuracy of the refractive soil models at low moisture. It is revealed that in soils with large clay content at frequencies below 20 MHz deviations from monotonic bound water CDC dependence on moisture are observed. The results can be used for improving the accuracy of soil moisture remote determination by microwave methods.

From measurements of the spectra of the complex permittivity of the moist soil it is shown that the application of the concept of freezing of unfrozen water in the frozen ground gives the error of 100 % for the calculation of the index. The authors point out that such a considerable error appears because of the presence of different types of unfrozen water in the soil.

The hardware-software complex which allows to define, with the minimum expenses, the spatial distribution and statistical characteristics of parameters of a micro relief of the spreading surface is described in the article. The micro relief in this case is understood as inequalities with the size from units of millimeters to units of decimeters. The size of a studied site of a surface is defined by the sizes of the laboratory stand and is limited to the first ten square meters. The horizontal and vertical extent of not uniformity of the micro relief can be defined: average value, dispersion, distribution by the sizes - its look and quantity of fashions. Creation of CMR in studied scale is also possible. The express determination of the sizes is made within model of the two-dimensional casual process which correlation function is calculated with the use of the theorem of Wiener-Hinchina. For the assessment of distribution by the sizes the algorithm of disconnection of contours is used. Creation of digital model of a micro relief proceeds with the use of stereo photos.

The authors present the results of detection of the complex dielectric permittivity of the bedded medium. A technique of measuring the dielectric parameters of two samples together with different dielectric permittivity. The possibility of determining the dielectric constant using both reflection and transmission coefficients is investigated. It is shown that this method can be used for measurements in the frequency range from 100 MHz to 4 GHz. The method for automatic calculating the dielectric parameters with the software MS Excel was implemented. Correct recovery of the dielectric permittivity is possible if the initial values do not differ from the true values by more than 10 %. The results can be used during the dielectric measurements.

The authors consider the question of detection of non-uniformities in the ice cover of fresh and light-salted water basins with the use of passive and active radio-detection in the microwave range. The paper contains ground for detection of salt inclusions in the ice. In the process of detection of non-uniformities comparable to the wavelength, practical application can find an active radar method.

Microwaves reflection at frequency of 1,4 GHz and 1,8 GHz from the structure “snow-soil” is considered. The results of field experiment with help of bistatic scheme are presented, the comparison of the results with the calculation data is made. It is shown that variation of a snow cover height produce considerable variations in reflected field level. It is revealed that experimental and numerical results partly meet. The obtained results can be used to refine the theoretical models of active and passive microwave remote sensing.

The article describes the results of experiments on radio sounding of forest vegetation with wideband pulse signals. The authors give notice to significant differences in changes of spectra of signals at interaction with different types of forests.

In the report the author present results of studies of the forest environment characteristics with the use of GPR “Eye-2”. The technique of operational remote determination of the forest environment density, based on GPR technology with accuracy of 5 %, is proposed.

The authors propose a method of measurement of back reflection. The values of the back reflection coefficient in reality soil are obtained. The comparison between the calculated and experimental data is made.

The report presents the results of Kotokel lake GPR survey, where an outbreak of “gafskaya” disease occured in 2008-2009. Convincing data on the stratification of the water column and sediments of the lake were received with the help of GPR “Eye-2”. Conclusion is made on essentially tectonic manner of occurence of the lake basin.

The results of radio-physical tomography of faults of active tectonic Baikal rift system in the zone of the middle Baikal are considered. Electro-physical properties and structure of the stratified-inhomogeneous rocks by surface-wave measurements in VLF-LF and VHF-UHF bands are identified. By the geo-radar method it was revealed the tectonic hade fault under the Baikal dunes, in the area of the resort Goryachinsk beach.

Estimations of the zenith troposphere delay (ZTD) detected at primary GPS data processing using GAMIT program are received on the base of multiyear measurements of radio signals on a net of regular GPS stations of ULAZ, IRKT and BADG spaced out up to 230 km. ZTD reflects variations of different atmosphere processes. The detailed analysis of GPS data of the ULAZ station for the period of 1999-2011 is presented.

In the paper the authors consider techniques and algorithms for secondary processing and interpretation of iono-grams obtained with the help of chirp ionosonde operating in vertical and oblique sounding mode (VS and OS). The secondary processing of experimental ionograms is carried out on the base of primary data filtering with subsequent compression with a help of cellular automaton technique. Ionogram interpretation methods is based on modeling results for frequency dependences of propagation characteristics in the regime of long-term forecast and on results of experimental data processing. We also develop the algorithm for electron concentration profile restoration on the base of HFC selected tracks.

The results of ionosphere radiotomography information technology development are presented and the ways of their evolution are listed. The used algorithms, techniques and output information flows are described. This technology currently using in the construction of Russia geophysical environment monitoring system.

The results of subsurface radio sounding of the sedimentary rocks complexes in the delta of the river selenga are considered in the article. Electro-physical properties and the structure of the stratified-inhomogeneous rocks according to the surface-wave measurements in vlf-lf bands are identified. Integrated survey methodology of near surface layers of rocks by radioimpedance and vertical electric sounding methods is proposed.