Numerical Prediction of Scientific Balloon Trajectories While Considering Various Uncertainties

Abstract

Before launching a scientific balloon, one needs to precisely predict its trajectory to avoid any possible accidents, as there are no means to control the horizontal motion of the balloon once it is launched. Although earlier studies developed simulation programs that predicted the trajectory of a scientific balloon with reasonable accuracy, the simulated results were hardly the same as the actual balloon flight because there existed uncertainties in balloon trajectory prediction. To address the difference between the predicted and actual flight trajectories, the prediction should be probabilistic, which means the uncertainties involved in the calculation should be taken into account. In the present work, a numerical simulation program is developed to predict the trajectories of a balloon, while considering various uncertainties, with the use of a Monte Carlo simulation. Sensitivity studies are performed to identify the most dominant uncertainty parameter in the distribution of landing points of the balloon flight. Operational uncertainty represented by the amount of buoyant gas is shown to be the most significant source of the prediction error, although it can be overcome by controlling the amount of lifting gas during the actual flight.