Concept
The basic ODA system that focused purely on aim was complicated enough already, but taking into account the influence of air currents, winds and breeze, temperature, and drag on the trajectory of his attack among other things to ensure an absolutely accurate hit on the target made things much more difficult.
He had yet to come up with a way to account for that. This was perhaps even more difficult than the base ODA system.
('I only need to account for the atmospheric condition whenever and wherever the Sonic Bullet is along its trajectory.') Rui noted.
Only the atmospheric pocket immediately outside of the Sonic bullet could influence the sound pulse projectile at any given time, anything that was never going to come into contact with the Sonic Bullet would not be able to directly influence it.