Study on evaporation duct estimation from point-to-point propagation measurements

Studies are conducted to estimate the evaporation duct refractivity structure inversely using signal strength sampled in the point-to-point propagation measurements. The repulsive particle swarm optimisation (RPSO) is adopted as an efficient optimisation algorithm to improve the efficiency of the inverse process. To verify the performance of the RPSO algorithm, numerical simulations are done to compare it with genetic algorithm and particle swarm optimisation for a typical inverse problem in estimating evaporation duct height and transmitting distance simultaneously. Moreover, to get better inversion accuracy, a layered evaporation duct model is also adopted and further numerical study based on measured refractivity profiles clearly demonstrate the better performance of layered model over other models to exhibit a closer match to the sonde data.