"How?"
"So far, I have been thinking about refining our own search sonar." Tom explained that the new system he had in mind would send out a complex pulse—that is, an underwater sound wave with many harmonics instead of a single tone, sharp-peaked sound impulse.
"This will make it less likely that their antidetection gear will absorb all of it," Tom went on. "What's not absorbed will return as an echo. I'm also going to modify our receivers. But I've still not worked that out."
Bud nodded, his forehead puckered in a look of concentration. "So—?"
"So our sonar picks up all that hash, and by means of a computer setup filters out the sub's real echo from the shadow reflections."
"Hey! Sounds pretty cute," Bud said.
Tom broke into a dry chuckle. "Right—if I can do it." After that job, Tom added, he hoped to adapt his own antidetection methods to make hydrolung wearers safe from underwater detection. "And if the Jupiter prober hasn't been found by that time, Bud, I'm going to request the Navy to let us take over the search alone."
Bud gave a whistle of excitement at the possibility of new undersea adventures ahead. "Count me in, pal!"
The two boys broke off their conversation a short time later and went back to the Administration Building for lunch with Tom's father.
Mr. Swift greeted them with a smile as they entered the big double office. "Glad you could join me, boys! Chow's laid out quite a feast for us today."