Daniel Westin is a scientist.
Working for the Klae Resource company, a for-profit research facility financed with contracts from various organizations but primarily the U.S. military establishment, Westin and his wife, Kate, both possessed PhDs as well as expertise in apparently several branches of science but it was in the realm of teleportation they were hired to explore.
According to comments by their boss, Walter Carlson, they had been hard at work at that research for nearly the previous year. Considering the familiarity with which the Westins talked with Carlson, it is likely their history went further back and it is possible the Westins had been involved in other things first. Still, teleportation was their objective. They would not achieve that.
What Daniel Westin discovered was invisibility. He found a way to affect molecules of items hit by a special ray to not be affected by light beams such that the light would pass around the molecules and .... alright, that exceeds my understanding of it (the author in the recorded chronicle of the initial adventure of the Westins told it better).
The key thing that Westin realized was that there were not many practical uses for invisibility outside of childish pranks, largely harmless, and military application, something he was adjectly opposed to. When he started at Klae, he had made sure there was no doubt he would not be involved in making weapons and now he had discovered something that was undoubtedly going to be militarized.
So the Westins were against telling anyone and Carlson was for making income from it. The balance they eventually would strike would get Westin involved in numerous escapades for which he had no training but for which he had extremely good cover.