Now I'm mystified. There's no "own position" anywhere! Own course came from automatic input from the compass. Own speed, similarly came from the knot meter. We have that. Otherwise the TDC could not work at all!
Its function is to calculate torpedo paths based on the relative motions of own ship and target. If it did not have the function you desire, although you are confused as to what the function is, you could hit nothing with a torpedo.
Actually, that's wrong, because with the vector analysis method, we can use the TDC as a several hundred pound paperweight. By choosing special attack parameters (any own course and speed, any target course and speed
) we don't need the TDC at all.
It is reduced to a luxury, allowing us a variety of deadly attack methods and a vast flexibility to meet the requirements of our attack situations.