Введение. Геофизическая разведка на сегодня-основной метод пополнения знаний о потенциальных зале... more Введение. Геофизическая разведка на сегодня-основной метод пополнения знаний о потенциальных залежах полезных ископаемых. Из всего разнообразия методов геофизической разведки электромагнитные методы наряду с сейсмическими наиболее результативны. К самым распространенным электромагнитным методам разведки можно отнести магнитотеллурическое зондирование (МТЗ), предложенное в 1950-х годах А. Тихоновым и Л. Каньяром. Этот метод использует естественные геомагнитные вариации как мощный источник элеткромагнитной индукции в Земле. Методика МТЗ заключается в измерении вариаций естественных электрических и магнитных полей в ортогональных направлениях на земной поверхности. На основе соотношений между их спектрами рассчитываются передаточные функции среды, интерпретация которых дает возможность определять структуру распределения электропроводимости в Земле и строить модели геоэлектрического разреза для глубин от нескольких десятков метров до нескольких сотен километров. Как и каждый метод, МТЗ имеет ограничения. В частности, анализ 3D моделей, построенных на основании данных МТЗ, показывает, что распределение электрической проводимости в глубинных или приповерхностных структурах, содержащих проводящие включения, позволяет выделить разломы УДК 550.83.045
A new approach is developed to find a source of pre-EQ ULF electromagnetic activity of lithospher... more A new approach is developed to find a source of pre-EQ ULF electromagnetic activity of lithospheric origin. For separation and localization of EQ magnetic precursors a new polarization ellipse technique has been developed to process the measurements data acquired from 3-component magnetometers.
The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimi... more The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimized for the energy 100 GeV with the best parameters: the angular resolution ∼ 0.01°, the energy resolution ∼ 1%, and the proton rejection factor ∼ 10 6 , but is able to measure gamma-ray and electron + positron fluxes in the energy range from 100 MeV to 10 TeV. GAMMA-400 is aimed to a broad range of science topics, such as search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, as well as high-precision measurements of spectra of cosmicray electrons + positrons, and nuclei.
In the frame of the FP7 POPDAT project the Ionosphere Waves Service (IWS) has been developed and ... more In the frame of the FP7 POPDAT project the Ionosphere Waves Service (IWS) has been developed and opened for public access by ionosphere experts. IWS is forming a database, derived from archived ionospheric wave records to assist the ionosphere and Space Weather research, and to answer the following questions: How can the data of earlier ionospheric missions be reprocessed with current algorithms to gain more profitable results? How could the scientific community be provided with a new insight on wave processes that take place in the ionosphere? The answer is a specific and unique data mining service accessing a collection of topical catalogs that characterize a huge number of recorded occurrences of Whistler-like Electromagnetic Wave Phenomena, Atmosphere Gravity Waves, and Traveling Ionosphere Disturbances. IWS online service (http://popdat.cbk.waw.pl) offers end users to query optional set of predefined wave phenomena, their detailed characteristics. These were collected by target specific event detection algorithms in selected satellite records during database buildup phase. Result of performed wave processing thus represents useful information on statistical or comparative investigations of wave types, listed in a detailed catalog of ionospheric wave phenomena. The IWS provides wave event characteristics, extracted by specific software systems from data records of the selected satellite missions. The end-user can access targets by making specific searches and use statistical modules within the service in their field of interest. Therefore the IWS opens a new way in ionosphere and Space Weather research. The scientific applications covered by IWS concern beyond Space Weather also other fields like earthquake precursors, ionosphere climatology, geomagnetic storms, troposphere-ionosphere energy transfer, and trans-ionosphere link perturbations.
We advance the achievements of Interball-1 and other contemporary missions in exploration of the ... more We advance the achievements of Interball-1 and other contemporary missions in exploration of the magnetosheath-cusp interface. Extensive discussion of published results is accompanied by presentation of new data from a case study and a comparison of those data within the broader context of three-year magnetopause (MP) crossings by Interball-1. Multi-spacecraft boundary layer studies reveal that in ∼80% of the cases the interaction of the magnetosheath (MSH) flow with the high latitude MP produces a layer containing strong nonlinear turbulence, called the turbulent boundary layer (TBL). The TBL contains wave trains with flows at approximately the Alfvén speed along field lines and "diamagnetic bubbles" with small magnetic fields inside. A comparison of the multi-point measurements obtained on 29 May 1996 with a global MHD model indicates that three types of populating processes should be operative:-large-scale (∼few R E) anti-parallel merging at sites remote from the cusp;-medium-scale (few thousand km) local TBL-merging of fields that are anti-parallel on average;
GAMMA-400 is a future high-energy γ-ray telescope, designed to measure the fluxes of γ-rays and c... more GAMMA-400 is a future high-energy γ-ray telescope, designed to measure the fluxes of γ-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of dark matter particles, and to survey the celestial sphere in order to study point and extended sources of γ-rays, measure energy spectra of Galactic and extragalactic diffuse γ-ray emission, γ-ray bursts, and γ-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to ∼3000 GeV. Its angular resolution is ∼ 0.01 • (E γ > 100 GeV), and the energy resolution ∼ 1 % (E γ > 10 GeV). GAMMA-400 is planned to be launched on the Russian space platform Navigator in 2019. The GAMMA-400 perspectives in the search for dark matter in various scenarios are presented in this paper
The problem of calculation and measurement of fluxgate magnetometers magnetic noise (MN) is analy... more The problem of calculation and measurement of fluxgate magnetometers magnetic noise (MN) is analyzed. The theoretical approach to MN estimation is given and semi-empirical relations allowing MN calculation in all operation frequency band are deduced. It is shown that the MN density increment in the direction of extremely low frequency can be approximated by 1/f function where α ≈ 3/4, but exact α value is not important for MN calculation for periods up to 1 year. The experimental study of flux-gate magnetometer noise in wide frequency band is made and its results are discussed.
The decreasing of weight and dimensions of the new generation of space vehicles – micro- and nano... more The decreasing of weight and dimensions of the new generation of space vehicles – micro- and nanosatellites – allows us to place the sensors of scientific payload on short and simple booms or even on the satellite body. By this the electromagnetic cleanliness (EMC) of these satellites becomes a first priority question. The investigation methodology and special theoretical approach were developed, which allow determination the parameters and location of the magnetic source inside the tested body with high enough sensitivity and precision. The EMC test system composition is described as well as developed theoretical basis is discussed.
VARIANT is a joint international space experiment on current density measurements in ionospheric-... more VARIANT is a joint international space experiment on current density measurements in ionospheric-magnetospheric plasmas. The experiment will be performed onboard the Ukrainian remote sensing satellite SICH-1M, that will be launched in 2000 at the polar circular orbit with the inclination of around 83 ° and altitude 670±30 km. The scientific payload includes three instruments for registration of space current density: a split Langmuir probe, a Rogovski coil and a Faraday cup. The first two of these instruments are dedicated to measure current density variations and the last the particles ’ fluxes. The equipment also includes sensors for measurements of the electric and magnetic field fluctuations in the frequency range from 0.1 Hz to 40 kHz. Main objectives of the VARIANT mission are as follows: • direct comparison of the spectral characteristics of the electric and magnetic fields with the characteristics of the field aligned currents in the polar regions; mapping of the field align...
The paper describes the accredited magnetometer calibration facility of the Nurmijärvi Geophysi-c... more The paper describes the accredited magnetometer calibration facility of the Nurmijärvi Geophysi-cal Observatory of the Finnish Meteorological Institute. The magnetometer calibration is part of the Magnetic Calibration and Test Laboratory of the observatory, which was accredited by the Finnish Ac-
The calibration system for vector DC magnetometers of Nurmijarvi Geophysical Observatory (Finland... more The calibration system for vector DC magnetometers of Nurmijarvi Geophysical Observatory (Finland) is described. It is based on a three axes reference coil system and Observatory reference magnetometer. It is shown experimentally that the system allows to determine calibrated magnetometer parameters with an error about 0.02%. One important error source-influence of non-collinearity of reference and calibrated magnetometer axes- is analyzed and value of this error is estimated. Also additional possibilities of the Observatory infrastructure are described: determination of temperature errors of magnetometer’s sensor and electronics and long-term temporal drift study of up to 9 magnetometers simultaneously. 1.
For experimental investigations of wave processes in space plasma one of the main tasks is the de... more For experimental investigations of wave processes in space plasma one of the main tasks is the determination of dispersion relations between the wave vector and the frequency. The frequency analysis of fluctuations of magnetic field and electric current density in plasma is very efficient in this case. The measurements of the magnetic field fluctuations usually are made by a variety of magnetometers using well developed methods. Unfortunately, up to the moment there are no reliable measurements of space current density although some attempts to do it with an instrument called “Split Langmuir Probe ” were made. It is mainly because of high sensitivity of the sensor readings to photocurrent and/or to spacecraft potential. The spatial current density can be measured not only by split Langmuir probe, but also by a contactless probe of the type of Rogovski coil and by Faraday cup. The comparative analysis of such probes operation in near Earth plasma is very important for further develop...
Введение. Геофизическая разведка на сегодня-основной метод пополнения знаний о потенциальных зале... more Введение. Геофизическая разведка на сегодня-основной метод пополнения знаний о потенциальных залежах полезных ископаемых. Из всего разнообразия методов геофизической разведки электромагнитные методы наряду с сейсмическими наиболее результативны. К самым распространенным электромагнитным методам разведки можно отнести магнитотеллурическое зондирование (МТЗ), предложенное в 1950-х годах А. Тихоновым и Л. Каньяром. Этот метод использует естественные геомагнитные вариации как мощный источник элеткромагнитной индукции в Земле. Методика МТЗ заключается в измерении вариаций естественных электрических и магнитных полей в ортогональных направлениях на земной поверхности. На основе соотношений между их спектрами рассчитываются передаточные функции среды, интерпретация которых дает возможность определять структуру распределения электропроводимости в Земле и строить модели геоэлектрического разреза для глубин от нескольких десятков метров до нескольких сотен километров. Как и каждый метод, МТЗ имеет ограничения. В частности, анализ 3D моделей, построенных на основании данных МТЗ, показывает, что распределение электрической проводимости в глубинных или приповерхностных структурах, содержащих проводящие включения, позволяет выделить разломы УДК 550.83.045
A new approach is developed to find a source of pre-EQ ULF electromagnetic activity of lithospher... more A new approach is developed to find a source of pre-EQ ULF electromagnetic activity of lithospheric origin. For separation and localization of EQ magnetic precursors a new polarization ellipse technique has been developed to process the measurements data acquired from 3-component magnetometers.
The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimi... more The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimized for the energy 100 GeV with the best parameters: the angular resolution ∼ 0.01°, the energy resolution ∼ 1%, and the proton rejection factor ∼ 10 6 , but is able to measure gamma-ray and electron + positron fluxes in the energy range from 100 MeV to 10 TeV. GAMMA-400 is aimed to a broad range of science topics, such as search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, as well as high-precision measurements of spectra of cosmicray electrons + positrons, and nuclei.
In the frame of the FP7 POPDAT project the Ionosphere Waves Service (IWS) has been developed and ... more In the frame of the FP7 POPDAT project the Ionosphere Waves Service (IWS) has been developed and opened for public access by ionosphere experts. IWS is forming a database, derived from archived ionospheric wave records to assist the ionosphere and Space Weather research, and to answer the following questions: How can the data of earlier ionospheric missions be reprocessed with current algorithms to gain more profitable results? How could the scientific community be provided with a new insight on wave processes that take place in the ionosphere? The answer is a specific and unique data mining service accessing a collection of topical catalogs that characterize a huge number of recorded occurrences of Whistler-like Electromagnetic Wave Phenomena, Atmosphere Gravity Waves, and Traveling Ionosphere Disturbances. IWS online service (http://popdat.cbk.waw.pl) offers end users to query optional set of predefined wave phenomena, their detailed characteristics. These were collected by target specific event detection algorithms in selected satellite records during database buildup phase. Result of performed wave processing thus represents useful information on statistical or comparative investigations of wave types, listed in a detailed catalog of ionospheric wave phenomena. The IWS provides wave event characteristics, extracted by specific software systems from data records of the selected satellite missions. The end-user can access targets by making specific searches and use statistical modules within the service in their field of interest. Therefore the IWS opens a new way in ionosphere and Space Weather research. The scientific applications covered by IWS concern beyond Space Weather also other fields like earthquake precursors, ionosphere climatology, geomagnetic storms, troposphere-ionosphere energy transfer, and trans-ionosphere link perturbations.
We advance the achievements of Interball-1 and other contemporary missions in exploration of the ... more We advance the achievements of Interball-1 and other contemporary missions in exploration of the magnetosheath-cusp interface. Extensive discussion of published results is accompanied by presentation of new data from a case study and a comparison of those data within the broader context of three-year magnetopause (MP) crossings by Interball-1. Multi-spacecraft boundary layer studies reveal that in ∼80% of the cases the interaction of the magnetosheath (MSH) flow with the high latitude MP produces a layer containing strong nonlinear turbulence, called the turbulent boundary layer (TBL). The TBL contains wave trains with flows at approximately the Alfvén speed along field lines and "diamagnetic bubbles" with small magnetic fields inside. A comparison of the multi-point measurements obtained on 29 May 1996 with a global MHD model indicates that three types of populating processes should be operative:-large-scale (∼few R E) anti-parallel merging at sites remote from the cusp;-medium-scale (few thousand km) local TBL-merging of fields that are anti-parallel on average;
GAMMA-400 is a future high-energy γ-ray telescope, designed to measure the fluxes of γ-rays and c... more GAMMA-400 is a future high-energy γ-ray telescope, designed to measure the fluxes of γ-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of dark matter particles, and to survey the celestial sphere in order to study point and extended sources of γ-rays, measure energy spectra of Galactic and extragalactic diffuse γ-ray emission, γ-ray bursts, and γ-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to ∼3000 GeV. Its angular resolution is ∼ 0.01 • (E γ > 100 GeV), and the energy resolution ∼ 1 % (E γ > 10 GeV). GAMMA-400 is planned to be launched on the Russian space platform Navigator in 2019. The GAMMA-400 perspectives in the search for dark matter in various scenarios are presented in this paper
The problem of calculation and measurement of fluxgate magnetometers magnetic noise (MN) is analy... more The problem of calculation and measurement of fluxgate magnetometers magnetic noise (MN) is analyzed. The theoretical approach to MN estimation is given and semi-empirical relations allowing MN calculation in all operation frequency band are deduced. It is shown that the MN density increment in the direction of extremely low frequency can be approximated by 1/f function where α ≈ 3/4, but exact α value is not important for MN calculation for periods up to 1 year. The experimental study of flux-gate magnetometer noise in wide frequency band is made and its results are discussed.
The decreasing of weight and dimensions of the new generation of space vehicles – micro- and nano... more The decreasing of weight and dimensions of the new generation of space vehicles – micro- and nanosatellites – allows us to place the sensors of scientific payload on short and simple booms or even on the satellite body. By this the electromagnetic cleanliness (EMC) of these satellites becomes a first priority question. The investigation methodology and special theoretical approach were developed, which allow determination the parameters and location of the magnetic source inside the tested body with high enough sensitivity and precision. The EMC test system composition is described as well as developed theoretical basis is discussed.
VARIANT is a joint international space experiment on current density measurements in ionospheric-... more VARIANT is a joint international space experiment on current density measurements in ionospheric-magnetospheric plasmas. The experiment will be performed onboard the Ukrainian remote sensing satellite SICH-1M, that will be launched in 2000 at the polar circular orbit with the inclination of around 83 ° and altitude 670±30 km. The scientific payload includes three instruments for registration of space current density: a split Langmuir probe, a Rogovski coil and a Faraday cup. The first two of these instruments are dedicated to measure current density variations and the last the particles ’ fluxes. The equipment also includes sensors for measurements of the electric and magnetic field fluctuations in the frequency range from 0.1 Hz to 40 kHz. Main objectives of the VARIANT mission are as follows: • direct comparison of the spectral characteristics of the electric and magnetic fields with the characteristics of the field aligned currents in the polar regions; mapping of the field align...
The paper describes the accredited magnetometer calibration facility of the Nurmijärvi Geophysi-c... more The paper describes the accredited magnetometer calibration facility of the Nurmijärvi Geophysi-cal Observatory of the Finnish Meteorological Institute. The magnetometer calibration is part of the Magnetic Calibration and Test Laboratory of the observatory, which was accredited by the Finnish Ac-
The calibration system for vector DC magnetometers of Nurmijarvi Geophysical Observatory (Finland... more The calibration system for vector DC magnetometers of Nurmijarvi Geophysical Observatory (Finland) is described. It is based on a three axes reference coil system and Observatory reference magnetometer. It is shown experimentally that the system allows to determine calibrated magnetometer parameters with an error about 0.02%. One important error source-influence of non-collinearity of reference and calibrated magnetometer axes- is analyzed and value of this error is estimated. Also additional possibilities of the Observatory infrastructure are described: determination of temperature errors of magnetometer’s sensor and electronics and long-term temporal drift study of up to 9 magnetometers simultaneously. 1.
For experimental investigations of wave processes in space plasma one of the main tasks is the de... more For experimental investigations of wave processes in space plasma one of the main tasks is the determination of dispersion relations between the wave vector and the frequency. The frequency analysis of fluctuations of magnetic field and electric current density in plasma is very efficient in this case. The measurements of the magnetic field fluctuations usually are made by a variety of magnetometers using well developed methods. Unfortunately, up to the moment there are no reliable measurements of space current density although some attempts to do it with an instrument called “Split Langmuir Probe ” were made. It is mainly because of high sensitivity of the sensor readings to photocurrent and/or to spacecraft potential. The spatial current density can be measured not only by split Langmuir probe, but also by a contactless probe of the type of Rogovski coil and by Faraday cup. The comparative analysis of such probes operation in near Earth plasma is very important for further develop...
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Papers by V. Korepanov