Presentation on theme: "AN ELECTRON DENSITY PROFILE MODEL FOR THE SOUTH AFRICAN IONOSPHERE Lee-Anne McKinnell Physics Department, Rhodes University, Grahamstown, South Africa."— Presentation transcript:
AN ELECTRON DENSITY PROFILE MODEL FOR THE SOUTH AFRICAN IONOSPHERE Lee-Anne McKinnell Physics Department, Rhodes University, Grahamstown, South Africa Space Physics Group, Hermanus Magnetic Observatory (HMO), Hermanus, South Africa
Neural Networks Training a computer to learn the relationship between a given set of inputs and a corresponding output highly suitable for non-linear relationships Main requirement -- an archived database describing the history of the relationship South African region Grahamstown, n(h) profile data from 1996, characteristics from 1973 Louisvale & Madimbo, n(h) profile data from 2000
SABIM Model South African region Bottomside ionospheric model Electron density profile Several NNs combined Special Features F1 Probability Network Smoothing technique Criterion for optimisation rms error on individual parameters Ability to reproduce realistic profiles
SABIM South African Bottomside Ionospheric Model Day Number Solar Activity Hour Magnetic Activity Electron Density Profile Model Geomagnetic position info Neural Network based empirical ionospheric model for the South African region
E layer Profile Is E layer predictable? E limits NN Predict E layer foE, hmE, E profile NNs Determining the probability of an F1 layer F1 Probability NN Output determines 1) or 2) or 3) 1) No F1 layer F2NN 2) F1 layer definite F1F2NN 3) F1 layer in L condition L Algorithm Smoothing Technique The Model F layer Profile F2 Layer Network Included Peak parameters – foF2, hmF2 Chebyshev coefficients Profile constructed foF2 – global foF2 network used F1 Layer Network Included Peak parameters – foF1, hmF1 Chebyshev coefficients Profile constructed L-algorithm, weighted avg btn F1 and No F1
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