23rd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics
The lower neutral part of the atmosphere (troposphere) where the GNSS signals are refracted is on... more The lower neutral part of the atmosphere (troposphere) where the GNSS signals are refracted is one of the reasons for the errors in the accuracy of GPS positioning. The total zenith tropospheric delay (ZTD) is the difference between the assumed straight line along which the GPS signal propagates at the speed of light in a vacuum and the actual path from source to receiver. Atmospheric water vapor affects the speed of propagation of GPS signals, and it is characterized by rapid variability as well as a significant mutual influence on the variability of other meteorological parameters. The possibility of determining the content of water vapor in a conventional vertical column to the level of the upper part of the troposphere using the GPS measurement method, as well as using meteorological data is considered. The results of processing primary GPS data give continuous atmospheric data in the form of a total zenith tropospheric delay (ZTD). Data on the “wet” component of the total zenith tropospheric delay (ZWD) can be converted with very high reliability into the integrated water vapor (IWV) data above the observation point.
The altitude dependence of the electromagnetic field above the arctic path at a frequency of 300 ... more The altitude dependence of the electromagnetic field above the arctic path at a frequency of 300 kHz (GLONASS CCS) is considered. When comparing the altitude dependences of the modulus of the attenuation function |W| and field level E for the radio paths "ice-sea" and "sea" it is shown that the conditions for propagation of radio waves over ice-covered sea at reception altitudes up to 3-10 km are more favorable than over the open sea. It is established that the propagation over the ice paths depends on the height of the reception. The field of a vertical electric antenna over an “ice-sea” structure with highly inductive impedance exceeds the field of the earth's wave above the open sea. It decreases with increasing reception height. This effect is due to the concentration of the field above the highly inductive medium interface. Insignificant growth of the field above the sea occurs with an increase of the reception height.
Electrical resistivity (electrical conductivity) of water and bottom soil of the Barguzin Bay was... more Electrical resistivity (electrical conductivity) of water and bottom soil of the Barguzin Bay was studied by radio impedance soundings in VLF/LF bands, and the measurements were analysed. The georadar sounding method was used to investigate dielectric permittivity of freshwater ice (dielectric constant is ε=3.4). We developed the technique of radio impedance sounding from the ice surface of Lake Baikal for measuring the electrical resistance of bottom soil in the water area, and applied this technique to a layered model of a medium with a base showing poor/good conductivity. Geoelectric models were constructed for the Barguzin Bay coast and the southern Lake Baikal. The geoelectrical section (GES) of the water area can be useful for earthquake forecasting from electromagnetic data, as well as for analysing the physical and chemical causes of the occurrence of ring structures on the ice surface of Lake Baikal.
Radio wave propagation techniques have been very rarely applied to investigate tectonic fault zon... more Radio wave propagation techniques have been very rarely applied to investigate tectonic fault zones and geoelectric profiles of the Baikal rift zone. In our study, we used a combination of ground-penetrating radar (GPR) and radio impedance techniques in order to identify and investigate tectonic crustal fault zones in the study area. Using soundings in the super-long, long and ultra short radio wave ranges (from tens of KHz to few GHz), we detected the tectonic fault zones in the seismically active Baikal rift zone, specifically in the Tunka depression and the areas of Southern Baikal and Kotokel lakes. Faults and fault zones were identified from impedance variations and changes in the geoelectric profiles by analyzing the radio impedance profiles and soundings in the super-long and long radio wave ranges. The georadiolocation of fault structures in the ultra-short wave range made it possible to differentiate the patterns of tectonic disturbances up to individual seismic dislocations in sedimentary and crystalline rocks and to determine the kinematics of movements in the fault zones. The techniques used in this study complement each other and ensure obtaining adequate quantitative descriptions of the study objects. By integrating various techniques of radio wave diagnostics, it is possible to obtain more detailed information on the structures of the tectonic fault zones. The results obtained in this study and the radio impedance and GPR sounding and profiling techniques developed to investigate a heterogeneous underlying medium can be used in seismological and geological engineering surveys of the eastern and northern regions of Russia.
The water vapor content is calculated in a conditional vertical column to the tropopause level fr... more The water vapor content is calculated in a conditional vertical column to the tropopause level from remote sensing data on the lower atmosphere. The calculations are based on GPS measurements, surface meteorological data and vertical meteorological profiles produced by radiosondes. A total zenith tropospheric delay (ZTD) is estimated as a difference between an estimated straight line, along which the GPS signal propagates in vacuum, and a length of the path between the signal source and the receiver, which is refracted in the real medium. A direct correlation is noted between changes in the 'wet' component of the tropospheric delay of the GPS signal and variations in the moisture content of the troposphere. A 'wet' component value of the tropospheric delay can be converted with a very high confidence into a value of integral water vapor above the observation point. In order to determine the integral water vapor amounts over the ULAB (Ulaanbaatar) permanent GPS monitoring station, empirical equations were used for the linear regressions of the ratios of surface temperature and mean weighted temperature for the water vapor elasticity using the data of radiosondes launched in the city of Ulaanbaatar and Muren settlement. We studied the features of the dynamics of variations in the integral water vapor, surface values of atmospheric pressure, air temperature and precipitation volumes over the ULAB station, using the data of July 2016.
Presented are the results of the winter 2014 radiophysical expedition, within the framework of wh... more Presented are the results of the winter 2014 radiophysical expedition, within the framework of which the Baikal ice cover was investigated by electromagnetic methods. The primary objectives the expedition were to detect irregularities in the ice cover, such as cracks and thawing steamed holes in the ice, and to determine the ice thickness and structure in the area of the thawing holes by the GPR sounding method. We used in the experiments the OKO-2 ground-penetrating radar (GPR) of the decimeter band and the nanosecond radar with the wavelength of 3 cm. The measurements were made carried out from the Khivus hovercraft and from the UAZ automobile. The ice thickness of Lake Baikal was determined by non-contact electromagnetic measurement methods. Radargrams of reflected signals from the ice cover are presented. Radar patterns of reflected signals from artificial irregularities of the ice cover were obtained by the short-pulse radar method. The concept of radiophysical monitoring is suggested, which provides a means of determining the ice cover parameters of a water body with high spatial resolution. We present an integral approach to investigating the conditions of the ice cover in order to integrate different physicochemical methods for diagnosing the objects studied. A further development of the concept of integrated ice cover research, and the creation of the monitoring network involves solving a number of scientific and engineering tasks that include developing physical models and information and measurement systems as well as the rationale for an integrated monitoring network.
The paper demonstrates that the conditions of LF-MF-HF radio wave propagation over the "ice-sea" ... more The paper demonstrates that the conditions of LF-MF-HF radio wave propagation over the "ice-sea" structure with highly inductive impedance are more favorable than over the sea without ice because of the appearance of surface electromagnetic waves (SEW). It was determined that the conditions of radio wave propagation over ice paths depend on a frequency, ice thickness and distance from the transmitter within the 100 kHz-5 MHz range on the paths with ice thickness from 0,6 to 2,7 m.
The Global Positioning System (GPS) based on satellites and the networks of dual frequency receiv... more The Global Positioning System (GPS) based on satellites and the networks of dual frequency receivers are actively used for geodetic and geophysical applications, as well as for studying the ionosphere and troposphere. The atmospheric water content is in the focus of research as a key parameter for determining of the accuracy of weather forecasting and hydrological monitoring. The precision of atmospheric water content calculations depends on the accuracy of determination of the delays of signals propagating from GPS satellites to ground-based GPS receivers when geodynamic measurements are conducted. This paper describes a technique that allows us to estimate the integrated water vapor (IWV) in the atmosphere from measurements of GPS satellite signal delays. We consider remote sensing of the lower atmosphere by GPS measurements to detect the water vapor content in the conventional vertical column to the top level of the troposphere (up to 12 km above the Earth's surface). In studies of the propagation of signals from GPS satellites to ground receivers, the atmospheric water vapor is taken into account as a 'wet' component (ZWD) of the zenith tropospheric delay (ZTD). ZTD is the sum of ZHD (hydrostatic or 'dry' delay) and ZWD ('wet' delay). ZWD values can be converted with a very high confidence in integrated water vapor (IWV) values for each installed GPS receiver.
A database of continuous measurements of the VLF pulsed flux of the natural electromagnetic field... more A database of continuous measurements of the VLF pulsed flux of the natural electromagnetic field of the Earth (NEMFE) in southern Siberia during the period from March 31, 2008 to the present was created. Analysis of long-term continuous observations has shown that NEMFE diurnal variations have stable seasonal changes. A high interannual correlation coefficient of NEMFE diurnal variations for the same months in 2008–2014 was discovered. The analysis of data from spaced recorders has shown a high degree of spatial correlation, which indicates a single local mechanism of the NEMFE formation.
2016 IEEE International Conference on Mathematical Methods in Electromagnetic Theory (MMET), 2016
The article demonstrates that the conditions of LF-MF-HF radio wave propagation over the “ice-sea... more The article demonstrates that the conditions of LF-MF-HF radio wave propagation over the “ice-sea” structure with highly inductive impedance are more favorable than over the sea without ice because of the appearance of surface electromagnetic waves (SEW). It was determined that the conditions of radio wave propagation over ice paths depend on a frequency, ice thickness and distance from the transmitter within the 100 kHz - 5 MHz range on the paths with ice thickness from 0,6 to 2,7 meters.
An electrometric method to determine the surface impedance of an ice–sea water bilayer system is ... more An electrometric method to determine the surface impedance of an ice–sea water bilayer system is suggested. The complex impedance (its magnitude and phase) of this system is determined at very low, low, and medium frequencies from electrometric, rather than radio, measurements. For the ice–sea water system, it is sufficient to determine the conductivity and thickness of a water sample from drilling data.
21st International Symposium Atmospheric and Ocean Optics: Atmospheric Physics, 2015
Predictive map of geoelectric sections of the North China on a scale of 1 : 2 500 000, necessary ... more Predictive map of geoelectric sections of the North China on a scale of 1 : 2 500 000, necessary for calculation of propagation of VLF-MF radiowaves, is constructed. Taking into account the layered structure of the underlying medium, this map is capable of increasing the accuracy of electromagnetic field calculations by 1.5-3 times as compared to the Morgan-Maxwell map. The methodology of the geoelectric mapping is described. The studies of electrical properties of layered media by combined radio and geophysical methods in a variety of natural and geological conditions, and the proposed method of geoelectric mapping have resulted in the construction of a new generation of maps showing the electrical properties of the underlying medium that account for the layered structure of the crust and have no analogues in the world.
Radioimpedance measurements are taken at two sites on ice in the coastal area of Lake Baikal. Fro... more Radioimpedance measurements are taken at two sites on ice in the coastal area of Lake Baikal. From these full-scale measurements for a water-bottom soil system, a two-layer geoelectric section is restored; namely, the resistivities of a water layer and bottom soil are determined and the thickness of the water layer is measured. For example, the following values are obtained at one of the sites: water resistivity ρw = 120 Ω m, bottom soil resistivity ρb = 1400 Ω m, and depth h = 5.5 m. These values are in agreement with published data. The suggested method or geoelectric section restoration is applicable to a thin water layer near the coast.
2014 24th International Crimean Conference Microwave & Telecommunication Technology, 2014
The results of numerical simulation of the propagation of UHF radio waves over the plane strongly... more The results of numerical simulation of the propagation of UHF radio waves over the plane strongly-inductive surface are presented. Numerical simulation showed the appearance of surface electromagnetic wave over the structure of the “dielectric on conductor” at the frequencies of the radio-navigation system GPS L1=1575.42 MHz and L2 = 1227.6 MHz.
23rd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics
The lower neutral part of the atmosphere (troposphere) where the GNSS signals are refracted is on... more The lower neutral part of the atmosphere (troposphere) where the GNSS signals are refracted is one of the reasons for the errors in the accuracy of GPS positioning. The total zenith tropospheric delay (ZTD) is the difference between the assumed straight line along which the GPS signal propagates at the speed of light in a vacuum and the actual path from source to receiver. Atmospheric water vapor affects the speed of propagation of GPS signals, and it is characterized by rapid variability as well as a significant mutual influence on the variability of other meteorological parameters. The possibility of determining the content of water vapor in a conventional vertical column to the level of the upper part of the troposphere using the GPS measurement method, as well as using meteorological data is considered. The results of processing primary GPS data give continuous atmospheric data in the form of a total zenith tropospheric delay (ZTD). Data on the “wet” component of the total zenith tropospheric delay (ZWD) can be converted with very high reliability into the integrated water vapor (IWV) data above the observation point.
The altitude dependence of the electromagnetic field above the arctic path at a frequency of 300 ... more The altitude dependence of the electromagnetic field above the arctic path at a frequency of 300 kHz (GLONASS CCS) is considered. When comparing the altitude dependences of the modulus of the attenuation function |W| and field level E for the radio paths "ice-sea" and "sea" it is shown that the conditions for propagation of radio waves over ice-covered sea at reception altitudes up to 3-10 km are more favorable than over the open sea. It is established that the propagation over the ice paths depends on the height of the reception. The field of a vertical electric antenna over an “ice-sea” structure with highly inductive impedance exceeds the field of the earth's wave above the open sea. It decreases with increasing reception height. This effect is due to the concentration of the field above the highly inductive medium interface. Insignificant growth of the field above the sea occurs with an increase of the reception height.
Electrical resistivity (electrical conductivity) of water and bottom soil of the Barguzin Bay was... more Electrical resistivity (electrical conductivity) of water and bottom soil of the Barguzin Bay was studied by radio impedance soundings in VLF/LF bands, and the measurements were analysed. The georadar sounding method was used to investigate dielectric permittivity of freshwater ice (dielectric constant is ε=3.4). We developed the technique of radio impedance sounding from the ice surface of Lake Baikal for measuring the electrical resistance of bottom soil in the water area, and applied this technique to a layered model of a medium with a base showing poor/good conductivity. Geoelectric models were constructed for the Barguzin Bay coast and the southern Lake Baikal. The geoelectrical section (GES) of the water area can be useful for earthquake forecasting from electromagnetic data, as well as for analysing the physical and chemical causes of the occurrence of ring structures on the ice surface of Lake Baikal.
Radio wave propagation techniques have been very rarely applied to investigate tectonic fault zon... more Radio wave propagation techniques have been very rarely applied to investigate tectonic fault zones and geoelectric profiles of the Baikal rift zone. In our study, we used a combination of ground-penetrating radar (GPR) and radio impedance techniques in order to identify and investigate tectonic crustal fault zones in the study area. Using soundings in the super-long, long and ultra short radio wave ranges (from tens of KHz to few GHz), we detected the tectonic fault zones in the seismically active Baikal rift zone, specifically in the Tunka depression and the areas of Southern Baikal and Kotokel lakes. Faults and fault zones were identified from impedance variations and changes in the geoelectric profiles by analyzing the radio impedance profiles and soundings in the super-long and long radio wave ranges. The georadiolocation of fault structures in the ultra-short wave range made it possible to differentiate the patterns of tectonic disturbances up to individual seismic dislocations in sedimentary and crystalline rocks and to determine the kinematics of movements in the fault zones. The techniques used in this study complement each other and ensure obtaining adequate quantitative descriptions of the study objects. By integrating various techniques of radio wave diagnostics, it is possible to obtain more detailed information on the structures of the tectonic fault zones. The results obtained in this study and the radio impedance and GPR sounding and profiling techniques developed to investigate a heterogeneous underlying medium can be used in seismological and geological engineering surveys of the eastern and northern regions of Russia.
The water vapor content is calculated in a conditional vertical column to the tropopause level fr... more The water vapor content is calculated in a conditional vertical column to the tropopause level from remote sensing data on the lower atmosphere. The calculations are based on GPS measurements, surface meteorological data and vertical meteorological profiles produced by radiosondes. A total zenith tropospheric delay (ZTD) is estimated as a difference between an estimated straight line, along which the GPS signal propagates in vacuum, and a length of the path between the signal source and the receiver, which is refracted in the real medium. A direct correlation is noted between changes in the 'wet' component of the tropospheric delay of the GPS signal and variations in the moisture content of the troposphere. A 'wet' component value of the tropospheric delay can be converted with a very high confidence into a value of integral water vapor above the observation point. In order to determine the integral water vapor amounts over the ULAB (Ulaanbaatar) permanent GPS monitoring station, empirical equations were used for the linear regressions of the ratios of surface temperature and mean weighted temperature for the water vapor elasticity using the data of radiosondes launched in the city of Ulaanbaatar and Muren settlement. We studied the features of the dynamics of variations in the integral water vapor, surface values of atmospheric pressure, air temperature and precipitation volumes over the ULAB station, using the data of July 2016.
Presented are the results of the winter 2014 radiophysical expedition, within the framework of wh... more Presented are the results of the winter 2014 radiophysical expedition, within the framework of which the Baikal ice cover was investigated by electromagnetic methods. The primary objectives the expedition were to detect irregularities in the ice cover, such as cracks and thawing steamed holes in the ice, and to determine the ice thickness and structure in the area of the thawing holes by the GPR sounding method. We used in the experiments the OKO-2 ground-penetrating radar (GPR) of the decimeter band and the nanosecond radar with the wavelength of 3 cm. The measurements were made carried out from the Khivus hovercraft and from the UAZ automobile. The ice thickness of Lake Baikal was determined by non-contact electromagnetic measurement methods. Radargrams of reflected signals from the ice cover are presented. Radar patterns of reflected signals from artificial irregularities of the ice cover were obtained by the short-pulse radar method. The concept of radiophysical monitoring is suggested, which provides a means of determining the ice cover parameters of a water body with high spatial resolution. We present an integral approach to investigating the conditions of the ice cover in order to integrate different physicochemical methods for diagnosing the objects studied. A further development of the concept of integrated ice cover research, and the creation of the monitoring network involves solving a number of scientific and engineering tasks that include developing physical models and information and measurement systems as well as the rationale for an integrated monitoring network.
The paper demonstrates that the conditions of LF-MF-HF radio wave propagation over the "ice-sea" ... more The paper demonstrates that the conditions of LF-MF-HF radio wave propagation over the "ice-sea" structure with highly inductive impedance are more favorable than over the sea without ice because of the appearance of surface electromagnetic waves (SEW). It was determined that the conditions of radio wave propagation over ice paths depend on a frequency, ice thickness and distance from the transmitter within the 100 kHz-5 MHz range on the paths with ice thickness from 0,6 to 2,7 m.
The Global Positioning System (GPS) based on satellites and the networks of dual frequency receiv... more The Global Positioning System (GPS) based on satellites and the networks of dual frequency receivers are actively used for geodetic and geophysical applications, as well as for studying the ionosphere and troposphere. The atmospheric water content is in the focus of research as a key parameter for determining of the accuracy of weather forecasting and hydrological monitoring. The precision of atmospheric water content calculations depends on the accuracy of determination of the delays of signals propagating from GPS satellites to ground-based GPS receivers when geodynamic measurements are conducted. This paper describes a technique that allows us to estimate the integrated water vapor (IWV) in the atmosphere from measurements of GPS satellite signal delays. We consider remote sensing of the lower atmosphere by GPS measurements to detect the water vapor content in the conventional vertical column to the top level of the troposphere (up to 12 km above the Earth's surface). In studies of the propagation of signals from GPS satellites to ground receivers, the atmospheric water vapor is taken into account as a 'wet' component (ZWD) of the zenith tropospheric delay (ZTD). ZTD is the sum of ZHD (hydrostatic or 'dry' delay) and ZWD ('wet' delay). ZWD values can be converted with a very high confidence in integrated water vapor (IWV) values for each installed GPS receiver.
A database of continuous measurements of the VLF pulsed flux of the natural electromagnetic field... more A database of continuous measurements of the VLF pulsed flux of the natural electromagnetic field of the Earth (NEMFE) in southern Siberia during the period from March 31, 2008 to the present was created. Analysis of long-term continuous observations has shown that NEMFE diurnal variations have stable seasonal changes. A high interannual correlation coefficient of NEMFE diurnal variations for the same months in 2008–2014 was discovered. The analysis of data from spaced recorders has shown a high degree of spatial correlation, which indicates a single local mechanism of the NEMFE formation.
2016 IEEE International Conference on Mathematical Methods in Electromagnetic Theory (MMET), 2016
The article demonstrates that the conditions of LF-MF-HF radio wave propagation over the “ice-sea... more The article demonstrates that the conditions of LF-MF-HF radio wave propagation over the “ice-sea” structure with highly inductive impedance are more favorable than over the sea without ice because of the appearance of surface electromagnetic waves (SEW). It was determined that the conditions of radio wave propagation over ice paths depend on a frequency, ice thickness and distance from the transmitter within the 100 kHz - 5 MHz range on the paths with ice thickness from 0,6 to 2,7 meters.
An electrometric method to determine the surface impedance of an ice–sea water bilayer system is ... more An electrometric method to determine the surface impedance of an ice–sea water bilayer system is suggested. The complex impedance (its magnitude and phase) of this system is determined at very low, low, and medium frequencies from electrometric, rather than radio, measurements. For the ice–sea water system, it is sufficient to determine the conductivity and thickness of a water sample from drilling data.
21st International Symposium Atmospheric and Ocean Optics: Atmospheric Physics, 2015
Predictive map of geoelectric sections of the North China on a scale of 1 : 2 500 000, necessary ... more Predictive map of geoelectric sections of the North China on a scale of 1 : 2 500 000, necessary for calculation of propagation of VLF-MF radiowaves, is constructed. Taking into account the layered structure of the underlying medium, this map is capable of increasing the accuracy of electromagnetic field calculations by 1.5-3 times as compared to the Morgan-Maxwell map. The methodology of the geoelectric mapping is described. The studies of electrical properties of layered media by combined radio and geophysical methods in a variety of natural and geological conditions, and the proposed method of geoelectric mapping have resulted in the construction of a new generation of maps showing the electrical properties of the underlying medium that account for the layered structure of the crust and have no analogues in the world.
Radioimpedance measurements are taken at two sites on ice in the coastal area of Lake Baikal. Fro... more Radioimpedance measurements are taken at two sites on ice in the coastal area of Lake Baikal. From these full-scale measurements for a water-bottom soil system, a two-layer geoelectric section is restored; namely, the resistivities of a water layer and bottom soil are determined and the thickness of the water layer is measured. For example, the following values are obtained at one of the sites: water resistivity ρw = 120 Ω m, bottom soil resistivity ρb = 1400 Ω m, and depth h = 5.5 m. These values are in agreement with published data. The suggested method or geoelectric section restoration is applicable to a thin water layer near the coast.
2014 24th International Crimean Conference Microwave & Telecommunication Technology, 2014
The results of numerical simulation of the propagation of UHF radio waves over the plane strongly... more The results of numerical simulation of the propagation of UHF radio waves over the plane strongly-inductive surface are presented. Numerical simulation showed the appearance of surface electromagnetic wave over the structure of the “dielectric on conductor” at the frequencies of the radio-navigation system GPS L1=1575.42 MHz and L2 = 1227.6 MHz.
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Papers by M. Dembelov