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Geomagnetická aktivita a její vliv na ionosféru
Mošna, Zbyšek ; Koucká Knížová, Petra
Cl anek se zab yv a vazbou geomagnetick e aktivity na ionosf eru. Je pops an mechanismus pusoben poru sen eho meziplanetarního pole slune cn ho v etru na zemsk e magnetick e pole v r uzn ych oblastech (vysok e a n zk e s rky). V praktick e c asti jsou prezentov any v ysledky m e ren z vertik aln ho ionosf erick eho sondov an v obdob geomagneticky poru sen e situace z oblasti st redn ch s rek ze stanice Pr uhonice. Je uk az an pokles maxim aln elektronov e koncentrace a zm ena v y sek vrstvy F2.
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Scaling Analysis Applied to Ionospheric, Solar and Geomagnetic Data
Mošna, Zbyšek ; Koucká Knížová, Petra
Scaling analysis based on structure function zeta(q) computed using wavelet analysis and spectrum D(h) is used to study possible connection of ionospheric system with the solar and geomagnetic activity. Data from six ionospheric stations (critical frequency foF2), solar flux F10.7 and geomagnetic indices AE, Kp and Dst are used. Data of foF2 show scale invariance in the period range 2–32 day. Scaling properties of ionospheric data show strong dependence on geomagnetic latitude of the station. Similar distribution of values of scaling exponents h for ionospheric and geomagnetic activity AE and Kp suggests connection between these systems. Values of h for foF2 and F10.7 have different distribution which suggests weak connection between these systems at chosen periods.
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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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Automatic Visualization Method of Height–Time Development of Ionospheric Layers
Mošna, Zbyšek ; Koucká Knížová, Petra
An automatic method for visualization of variability of ionospheric plasma in terms of ionospheric layers is presented. Here, we use the virtual reflection height for visualization. We directly plot the height–time dependence using original raw digisonde outputs. It gives us an opportunity to promptly visualise the ionospheric digital data and locate events of the interest for further analysis. In this paper, we present a variability in height of E-layer with a special focus on the sporadic E-layer. The proposed method is applicable for any ionospheric region.
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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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