Abstract
For the improvement of the signal to noise ratio in an echo ranging system, the matched signal waveforms to be transmitted had already been analyzed theoretically, on the assumption that a matched filter is used in the receiving apparatus. But we could not find any example which considered actual sea conditions for sonors. The author calculated the matched signal waveforms in some typical conditions under which the sonar is ordinarily placed. The conditions are 1kc and 5kc carrier frequencies, ±2% and ±20% of carrier frequencies for band widths, and all combinations thereof. Comparing these results the author could make their tendencies and remarkable characteristics clear.
