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21 listopada br. w Ministerstwie Rozwoju odbyła się wyjątkowa konferencja podsumowująca 5 lat członkostwa Polski w Europejskiej Agencji Kosmicznej. Celem konferencji była prezentacja zaangażowania polskiego sektora kosmicznego w badania nad przestrzenią kosmiczną, jak również wskazanie kierunków dalszego rozwoju branży, która jest jednym z kluczowych sektorów wzmacniających innowacyjność i konkurencyjność światowych gospodarek.

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czwartek, 27 czerwca 2019 15:34

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- Aspect-sensitive scattering on polar ionospheric irregularities in HF radio propagation at high and middle latitudes

Radio signals of HF band propagate on long distances due to reflection or scattering from ionosphere. Mirror reflected signals propagating lower maximal usable frequency (MUF) are usually used for reliable communication. In this case an aspect-sensitive scattering on field-aligned plasma irregularities of aurora ovals plays the role of passive interference at high and middle latitude. For the case of HF propagation over the MUF, the aspect-sensitive scattering sometimes can provide so high level of signal intensity that sufficient for establishing a communication.

The work will consist of the next stages.

-   Carrying out of measurements on testing HF radio lines.

-   Processing the data and estimating the parameters of scattered signals.

-   Developing a model of aspect-sensitive scattering for specified radio links.

-   Verification of the model using experimental databases.

Study of the aspect-sensitive scattering of emission of discrete cosmic sources in the Earth’s ionosphere using LOFAR could be extended task of this work.

 

- Developing the techniques for prediction of HF propagation conditions at the high latitudes

Radio waves of high frequency (HF) band are widely used for providing the radio communication on large distances due to their ability to propagate by reflection from the Earth’s ionosphere. For improving the quality and reliability of communication a forecasting of propagation conditions for specified radio links is required. Relatively slow seasonal and diurnal variations of ionospheric parameters and their reaction on solar activity are predicted well in frames of modern ionospheric models. Unfortunately, quick small- and medium-scale disturbances in the polar ionosphere can’t be described yet in the frames of modern models. As a result, a dynamical forecast of only large-scale distribution of HF propagation conditions and its slow changes can be provided well. Therefore developing and upgrading the techniques for prediction of HF propagation in the quickly varying polar ionosphere remain an actual problem for radio sciences and operational radio services.

It is planned to do the following in frames of work.

- Establish the control radio links and to carry out the measurements of the conditions of HF propagation in the high latitudes.

- Process the data of HF measurements on the testing radio links.

- Analyze the HF signal parameters together with the data of ionosondes and other independent tools for diagnostics of the polar ionosphere.

- Develop the new and/or upgrade the existent experimental techniques for estimating the conditions of HF propagation using the data of ionospheric sounding on testing radio lines.

- Develop the new and/or upgrade the existent techniques for predicting the conditions of HF propagation.

- Verify the techniques for prediction using the accumulated data of measurements.

- Implement the developed techniques into the systems of operative prediction of the HF propagation conditions at the high latitudes.

Poprawiony: piątek, 28 czerwca 2019 12:45
 
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