A GP-MOEA/D Approach for Modelling Total Electron Content over Cyprus

Abstract-- V ertical T otal Electron Content (vTEC) is an iono-spheric characteristic used to derive the signal delay impo sed by the ionosphere on near-vertical trans-ionospheric link s. The major aim of this paper is to design a prediction model based o n the main factors that influence the variability of this param eter on a diurnal, seasonal and long-term time-scale. The model should be accurate and general (comprehensive) enough for efficiently approximating the high variations of vTEC. Howe ver, good approximation and generalization are conflicting obje ctives. For this reason a Genetic Programming (GP) with Multi-objec tive Evolutionary Algorithm based on Decomposition characteri stics (GP-MOEA/D) is designed and proposed for modeling vTEC over Cyprus. Experimental results show that the Multi-Objectiv e GPmodel, considering real vTEC measurements obtained over a period of 11 years, has produced a good approximation of the modeled parameter and can be implemented as a local model to account for the ionospheric imposed error in positioning . Particulary, the GP-MOEA/D approach performs better than a Single Objective Optimization GP, a GP with Non-dominated Sorting Genetic Algorithm-II (NSGA-II) characteristics a nd the previously proposed Neural Network-based approach in most cases. The ionosphere is defined as a region of the earth's upper atmosphere where sufficient ionisation can exist to affect t he propagation of radio waves. It ranges in height above the surface of the earth from approximately 50 km to 1000 km.