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Study of ionospheric F2 layer dynamics using Digisonde DPS-4 measurements in Pruhonice observatory
Kouba, Daniel ; Koucká Knížová, Petra (advisor) ; Ondrášková, Adriena (referee) ; Přech, Lubomír (referee)
Title: Ionospheric drift measurements Author: Daniel Kouba Department: Department of Surface and Plasma Science Supervisor: RNDr. Petra Koucká Knížová, Ph.D. Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic Abstract: This thesis deals with ionospheric drift measurements using Digisonde DPS-4. The results are divided into theoretical and practical part. It is shown that for drift data processing it is necessary to choose correct reflection points corresponding to drift movements first. The selection is made in three steps: restriction of Doppler frequency shift, height range selection, choice of the maximum zenith angle. After- wards it is possible to credibly estimate the vector of drift velocity. The experimental results of drift measurements are based on data from the Pru- honice station. To study the common behavior of ionospheric drifts during quiet conditions, the statistical characteristics of drift velocity components are investiga- ted in layers E and F during geomagnetic quiet year 2006. The maximal daily amplitude of horizontal velocity demonstrates the influence of geomagnetic activity. It is proved to be considerable in the F layer meanwhile it was not observed in the E layer. The effect of strong geomagnetic disturbances is shown at two examples of extreme storms. The...
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The Study of Leukaemia Specific Diagnostic and Prognostic Markers
Kouba, Daniel ; Hromadníková, Ilona (advisor)
In my theses I concentrated on examination of specific prognostic markers of acute myeloid leukemia, chronic myeloid leukemia and chronic lymphocytic leukemia. Today by AML diagnose the cytogenetic abnormalities are considered the main prognostic marker. Patients, whose prognostic group it is not possible to identify with certainty just on the bases of cytogenetic examination, can be stratified by proving the presence of specific gene mutations or high expression levels of of some genes. The most important and most frequently identified prognostic marker by AML is mutation of FLT3-LM. Protein coded by this gene is also a hypothetical aim of the treatment. The crucial diagnostic marker of CML is the gene bcr-abl, which, in most of the cases, is a product of t(22,9). The discovery of inhibitors of tyroxine kinase bcr-abl brought about a substantial change into the aproach of the treatment as well as into the prognose of the ill. Through examination of immunoglobulin heavy-chain gene mutation status it is possible to divide patients with CLL into two subgroups with different pathogenesis and advancement of the illness. Other prognostic data can be acquired from cytogenetic examination and from essay of the level of CD38 and ZAP-70.
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Digisonde measurement
Kouba, Daniel ; Mošna, Zbyšek ; Koucká Knížová, Petra ; Boška, Josef ; Rejfek, Luboš
Ionospheric station in Průhonice currently performs its measurements using Digisonda DPS 4D. The vertical profile of the electron concentration can be measured by ionospheric vertical sounding using Ionosonde and Digisonde. The electron concentration profile shows the location of the layers of the ionosphere, the D, E, F1 and F2 layers, and the electron concentration at a given height. Another way to study the behavior of the ionosphere is to measure Doppler shift in ionospheric plasma. The Průhonická observatory is part of the Digisond World Network. The measured data is immediately automatically sent to the GIRO database (http://ulcar.uml.edu/DIDBase/).
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Study of ionospheric F2 layer dynamics using Digisonde DPS-4 measurements in Pruhonice observatory
Kouba, Daniel ; Koucká Knížová, Petra (advisor) ; Ondrášková, Adriena (referee) ; Přech, Lubomír (referee)
Title: Ionospheric drift measurements Author: Daniel Kouba Department: Department of Surface and Plasma Science Supervisor: RNDr. Petra Koucká Knížová, Ph.D. Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic Abstract: This thesis deals with ionospheric drift measurements using Digisonde DPS-4. The results are divided into theoretical and practical part. It is shown that for drift data processing it is necessary to choose correct reflection points corresponding to drift movements first. The selection is made in three steps: restriction of Doppler frequency shift, height range selection, choice of the maximum zenith angle. After- wards it is possible to credibly estimate the vector of drift velocity. The experimental results of drift measurements are based on data from the Pru- honice station. To study the common behavior of ionospheric drifts during quiet conditions, the statistical characteristics of drift velocity components are investiga- ted in layers E and F during geomagnetic quiet year 2006. The maximal daily amplitude of horizontal velocity demonstrates the influence of geomagnetic activity. It is proved to be considerable in the F layer meanwhile it was not observed in the E layer. The effect of strong geomagnetic disturbances is shown at two examples of extreme storms. The...
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Ray-tracing simulations of electromagnetic waves in magnetospheric plasmas
Nečada, Marek ; Santolík, Ondřej (advisor) ; Kouba, Daniel (referee)
This work deals with simulations of wave propagation in magnetospheric plasmas, particularly with numerical ray tracing. It mentions some of the earlier ray tracing implementations that were used in studies of wave propagation in Earth's magnetosphere. The most important parts of linear plasma wave theory are outlined. Some of the existing numerical methods for solving the hot plasma dispersion relation are described. A new ray tracing program, NPR, is presented. It is capable of ray-tracing simulations in cold plasmas and also in non-relativistic hot plasmas via the WHAMP procedure.
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The Study of Leukaemia Specific Diagnostic and Prognostic Markers
Kouba, Daniel ; Hromadníková, Ilona (advisor)
In my theses I concentrated on examination of specific prognostic markers of acute myeloid leukemia, chronic myeloid leukemia and chronic lymphocytic leukemia. Today by AML diagnose the cytogenetic abnormalities are considered the main prognostic marker. Patients, whose prognostic group it is not possible to identify with certainty just on the bases of cytogenetic examination, can be stratified by proving the presence of specific gene mutations or high expression levels of of some genes. The most important and most frequently identified prognostic marker by AML is mutation of FLT3-LM. Protein coded by this gene is also a hypothetical aim of the treatment. The crucial diagnostic marker of CML is the gene bcr-abl, which, in most of the cases, is a product of t(22,9). The discovery of inhibitors of tyroxine kinase bcr-abl brought about a substantial change into the aproach of the treatment as well as into the prognose of the ill. Through examination of immunoglobulin heavy-chain gene mutation status it is possible to divide patients with CLL into two subgroups with different pathogenesis and advancement of the illness. Other prognostic data can be acquired from cytogenetic examination and from essay of the level of CD38 and ZAP-70.
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Impact of the troposphere on the inosphere
Koucká Knížová, Petra ; Mošna, Zbyšek ; Potužníková, Kateřina ; Boška, Josef ; Kouba, Daniel
Ionosphere represents weakly ionized plasma that reflects solar and geomagnetic activity and processes\nin the neutral atmosphere. Correlation of long time series of the ionospheric plasma critical frequencies,\nobtained by mean of vertical sounding from European stations, is analysed with respect to latitudinal and\nlongitudinal difference and surface distance of stations. Time series of critical frequencies are highly correlated\nreflecting the dominant solar influence. Correlation coefficients are high not only for raw data and subtracted\nmean courses but for fluctuations around mean as well. At the surface distance exceeding 1000 km and/ or about\n10 degrees of latitudinal difference between stations, the correlation coefficients of fluctuations decrease\nrapidly. Such effect is less visible on the latitudinal dependence, where the correlation coefficients decrease with\nincreasing distance with less pronounced threshold. We explain the existence of the ‘break point’ at 10 degrees\nin longitude and/or 1000 km by the ‘local’ influence of the neutral atmosphere and the wave activity. As a\npossible source of the common influence on scale 1000 km/10 degree we propose tropospheric systems that are\nknown to be an important source of atmospheric waves in a broad period range. Large tropospheric mesoscale\nsystems have typically up to 2000 km in size.
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Influence of Non-vertical Echoes to Ionogram Scaling
Kouba, Daniel ; Koucká Knížová, Petra
Digisonde DPS 4 replaced the older ionosonde IPS 42 KEL Aerospace in the Observatory Pruhonice in January 2004. Additional information about the wave polarization enables us to determine and to distinguish exactly between ordinary and extraordinary wave traces on the ionogram records. This new ability basically changes scaling of the ionograms comparing to the ionograms obtained by classical ionosondes. Digisonde measurements show that in some cases the interpretation of ionograms based on classical ionospheric soundings may lead to the systematic errors, which affect classical ionograms interpretation. We demonstrate possible significant misinterpretations of the ionograms obtained using the classical equipment that is not able to distinguish between ordinary and extraordinary modes and records only time of flight of the electromagnetic sounding pulse. We show the necessity to be careful in using an old ionosonde measurements and scaled data for further analysis.
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Study of Chance for Good DDA Drift Velocity Estimation for Ionospheric F-region Drift Measurements
Kouba, Daniel ; Koucká Knížová, Petra
Estimation of the plasma drift velocity measured by Digisonde depends on the number of reflection points and their distribution. In the paper we divide and analyse plasma drift measurements according to the number of reflection points. A detailed study of Digisonde drift measurement quality has not been published yet. Two extreme groups are selected for further detail analysis, the first one with less than 100 reflection points and the second with more than 800 points. Within the data in these groups we detect annular and diurnal variability. Measurements containing low number of the reflection points occur mainly around equinoxes and during day-time. On the contrary, maximum occurrence of the measurements with more than 800 points is in winter and summer. The lowest chance to register extreme number of the reflections is during afternoon and around sunset.
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