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SIMONe is a multistatic radar system, conceived and developed at IAP, used for the detection of meteor trails and deduction of winds from their Doppler velocities. Meteors ablate in the atmosphere at around 90km, the generated plasma is able to scatter/reflect radio waves. These reflections are detected, decoded and parameters like distance, signal strength, Doppler shift, decay time, and duration are derived. These parameters are used to deduce atmospheric neutral winds at these altitudes. In standard analysis, some detections are rejected from further processing to smooth the output (cleaning procedure).
The topic will be an investigation of these rejected values (outliers), motivated by the recent findings at IAP of large geophysical vertical velocities previously not expected.
The goal is to classify the outliers into geophysical and non-geophysical ones, taking into account their raw signal characteristics and their surrounding dynamics. The data will be taken from the SIMONe-Germany system, namely selected radar raw data and pre-analyzed parameter data, both in HDF5 format. Programming of this analysis is expected to be done in Python and should include besides the analysis and classification, graphical user interfaces that would facilitate the verification of the physical events.
The solar radiation is the primary source for the ionization of the higher and middle atmosphere. Given the actual solar radiation and solar zenith angle the different layers of the atmosphere are formed and vary in their intensity, namely the electron density content. The classical and accepted layers are named D, E, Es, F1, F2 spreading over 60-250+km altitude.
Radio waves emitted by HF radars are partially or totally reflected from these altitudes. Several decades ago also a "C"-layer around 50-60km altitude has been postulated, which was not widely accepted.
At IAP two radars near 3MHz are operated, one in Northern Norway and the other in Northern Germany, which are able to reflect signals from altitudes as low as around 50km.
This study will consist of two parts, detecting layers around 60km caused by precipitating particles, forming arcs in the spectral domain of the data. Besides the statistical analsis of the events, a kind of pattern recognition technique will be useful to unambiguously detect the events in spectral domain. The second part will be looking for such layers occurring at these altitudes, which are not related to particle precipitation.
For both types of layers we aim for a database of their occurrence. Thus, both preanalyzed data, but also original radar raw data is to be used together with appropriate pre-processing.